I. INTRODUCTION 

In at least four separate New Testament (NT) passages, an association exists between the two Greek words teleios and nepios. Whereas teleios means and is translated into the English word mature, the word nepios denotes a child. These passages then provide a clear and striking contrast; my purpose is to drive home the necessity for personal, continued spiritual growth in the life of every believer. 

The contrast between the two words should not be interpreted as good versus evil because, after being saved, every believer goes through a period of spiritual infancy—not to mention that we all act immature at times, no matter our age in Christ. Complete sanctification only occurs when we go to be with the Lord. The bottom line of these passages—and of the study—is this: we should not remain in a state of spiritual immaturity! Unfortunately for American Christianity, many believers are characterized by spiritual immaturity. How long have you known Christ as Lord and Savior? If it’s been a good while, do you nevertheless remain in a spiritual fog? 

Let’s begin by looking at each of these four passages that illuminate this contrast, juxtaposing spiritual immaturity with spiritual maturity. 

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And I, brethren, could not speak to you as to spiritual men, but as to men of flesh, as to infants in Christ. I gave you milk to drink, not solid food; for you were not yet able to receive it. Indeed, even now you are not yet able, for you are still fleshly. For since there is jealousy and strife among you, are you not fleshly, and are you not walking like mere men? (1 Corinthians 3:1–3) 

For everyone who partakes only of milk is not accustomed to the word of righteousness, for he is an infant. But solid food is for the mature, who because of practice have their senses trained to discern good and evil (Hebrews 5:13–14). 

Until we all attain to the unity of the faith, and of the knowledge of the Son of God, to a mature man, to the measure of the stature which belongs to the fullness of Christ. As a result, we are no longer to be children, tossed here and there by waves and carried about by every wind of doctrine, by the trickery of men, by craftiness in deceitful scheming (Ephesians 4:13–14). 

Brethren, do not be children in your thinking; yet in evil be infants, but in your thinking be mature (1 Corinthians 14:20).

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Before looking more closely at each of these passages and observing how they illustrate the stark contrast between spiritual immaturity and maturity, you may be already asking yourself this question: how do we grow out of the former and into the latter? The first two verses of Romans 12 spell out how the believer grows from infancy to maturity: 

Therefore I urge you, brethren, by the mercies of God, to present your bodies a living and holy sacrifice, acceptable to God, which is your spiritual service of worship. And do not be conformed to this world, but be transformed by the renewing of your mind, so that you may prove what the will of God is, that which is good and acceptable and perfect. 

As seen in this passage, spiritual growth occurs when you are transformed by the renewing of your mind. And the renewing of your mind happens at the rate by which you learn the Scriptures and obey them. Remember, importantly, Scripture states of itself in Hebrews 4:12: 

The word of God is living and active and sharper than any two-edged sword, and piercing as far as the division of soul and spirit, of both joints and marrow, and able to judge the thoughts and intentions of the heart (Hebrews 4:12). 

Accordingly, since Scripture is living and active, it has the power to transform us from childhood to adulthood to the degree we allow the Word to renew our mind. Therefore, renewal and transformation are tantamount to knowing and obeying the Word of God. To elaborate further, 2 Corinthians 10:5 instructs us to take… 

every thought captive to the obedience of Christ. 

Do you in any way block the Word from transforming your thinking? Is the Word—or the world—preeminent in your thinking? In a closer examination of these passages that contrast adults with infants, let’s examine some of the specific revealed indicators that characterize each category. Which of these characteristics identify you? 

II. THREE CHARACTERISTICS OF SPIRITUAL INFANTS 

Let us now exegete particular portions of the aforementioned passages of contrast (in the order I have listed them) in order to underscore the following summary identifiers of spiritual infancy. 

A. INFANTS DO NOT LISTEN 

I, brethren, could not speak to you as to spiritual men (1 Corinthians 3:1). 

Paul’s use of the word brethren denotes that he is addressing believers in the Church of Corinth. His point was that even though they were saved, he couldn’t communicate with them in a manner normal for mature Christians speaking with mature Christians. When both are spiritual men in Christ, believers can reason with one another from the Scriptures because both hold the Word in common as authoritative, the final arbiter for all of faith and practice. However, when a person says he is a believer but will not respond to the clear teachings and authority of the Word of God, classifying him or her as an infant is fair. Conversely, Paul had to speak to them as men of flesh, as to infants in Christ. He could only give them milk to drink and not solid food for [they] were not able to receive it. 

Milk contrasted with solid food is a fitting picture denoting the believer’s inability to digest the Word of God. Many American believers today are like children who want candy and dessert versus a regular, nutritious meal that will supply their real needs for strong, healthy growth, i.e., carbs versus protein. That observation leads me to say this: the mature in Christ dine not only on the Word, but also on commentaries, systematic theologies, Church history, Christian biographies, etc. How are your reading habits? How is your library coming?

Metaphorically, every serious believer needs to be in the weight room, downing protein shakes and watching his carb intake. 

Having stated that, all passages of Scripture contain milk and meat and are capable of ministering to the needs of all who are intent on listening to the Word, no matter their level of spiritual maturity. It is incumbent on both the teacher and the pupil to ascertain what God wants each one to learn from the passage under study. What is tragic, however, is for the pupils to demand that the teacher offer only milk and/or for the teacher never to go so deep as to challenge the students in areas where they are immature and sinning. For instance, as a teacher of God’s Word, I must say the following: those believers who sponsored the National Prayer Breakfast should be canceling it instead. Why would believers sponsor an event historically characterized by religious syncretism that hurts rather than helps the propagation of singular saving faith in Christ alone? Such syncretism invokes God’s wrath on our nation, not His blessing. 

The above is illustrative of the job of a Bible teacher per Paul’s admonition of his understudy, Timothy, in 2 Timothy 3:16–17. The spiritual leader/Bible teacher will undergo a stricter judgment ( James 3:1) and cannot shrink from declaring the whole counsel of God (Acts 20:27)—no matter how folks within the sound of his heralding may choose to respond to him. (Remember, America’s greatest theological mind, the uncompromising Jonathan Edwards, was thrown out of his church because he wouldn’t marry an elder’s child to a non-believer.) 

Generally speaking, the above present-day, relevant admonition illustrates my point: do you intently desire to listen to and obey the Word, or are you occupied with your own thinking and way of doing things? Remember: 

For everyone who partakes only of milk is not accustomed to the word of righteousness, for he is an infant (Hebrews 5:13). 

Babes in Christ tend to avoid strong doses of the Word because they know the Word will convict them of their wrongdoing and because their conscience will prod them to change. Although they may publicly and verbally accede to sola Scriptura, infants reject the authority of God’s Book when it trumps personal desires because, like a baby trying to digest a steak dinner, they are not accustomed (apeiros) to bowing to its right-way-ness. Believers who shrink from studying the Word telegraph their spiritual immaturity. Infants may even attempt to discredit the Word in their desires to rationalize and justify self-serving actions. 

B. INFANTS REBEL 

Indeed, even now you are not yet able, for you are still fleshly (1 Corinthians 3:2b–3:3a). 

The Corinthian believers had heard and received the gospel at a much earlier time, yet they still walked as though they weren’t saved by God through Christ. This disregard is grossly abnormal for any Christian. They were passive and/or rebellious regarding their new life and position in Him. They were rebelling against God’s command, for all believers are to walk by the Spirit, and you will not carry out the desire of the flesh (Galatians 5:16b). 

What are the desires of the flesh? They are evident in 1 John 2:16b: the lust of the flesh and the lust of the eyes and the boastful pride of life. Elsewhere Paul states, similarly, Do not quench the [Holy] Spirit (1 Thessalonians 5:19). The ministry of the Holy Spirit in the life of the believer secures the victory over (respective to 1 John 2:16) sexual lust, covetousness, and self-centeredness—sins all too present on the Hill. The power of the ministry of the Holy Spirit parallels the degree to which believers allow the Word of God to richly dwell within them (cf. Ephesians 5:18 and Colossians 3:16). 

It is biblically infantile for anyone to name the name of Christ yet continue to display spiritual immaturity and latent insurgency toward God by refusing to adhere to the precepts of His Word. Not only is throwing protein-rich food from the highchair unacceptable, but it is also rank rebellion. 

C. INFANTS DISPLAY JEALOUSY AND CAUSE STRIFE 

Notice the progression here relative to the first three characteristics: immature believers don’t listen to good counsel, they rebel, and thus they affect others in the body of Christ: 

For since there is jealousy and strife among you, are you not fleshly, and are you not walking like mere men? (1 Corinthians 3:3). 

Where jealousy exists attitudinally, strife will result visibly. The former is a sinful, immature emotional feeling, and the latter is a manifestation of selfishness and provocation. Accordingly, immature believers cause division in the body of Christ. Why? Because in their infancy, it’s still all about them versus God’s glory. The babe in Christ has difficulty putting away the old self (cf. Ephesians 4:31), his self-centered ambitions, and his quest for significance. But in truth, as Paul said of himself in Galatians 2:20, “I have been crucified with Christ; and it is no longer I who live….” Every mature believer must live with an attitude of being dead to self. 

So why all the quest for personal glory? Our goal as believers is God’s glory! Accordingly, when faced with a decision regarding personal interests over those of the body of Christ, we are to choose the latter. Infants in Christ, states our passage, walk like mere men. Or said another way, they act like non-believers. 

III. FOUR CHARACTERISTICS OF SPIRITUAL ADULTS

A. ADULTS ARE TRAINED AND DISCERNING 

But solid food is for the mature, who because of practice have their senses trained to discern good and evil (Hebrews 5:14). 

This contrasting portion of the second verse of Hebrews 5:13–14 is easy to see and understand. Spiritually mature individuals, because of their regular diet of the Word, possess the ability to discern truth from error. They are trained to see life through the lens of the Book penned by the Author of life. A parallel passage to this is 1 John 2:12–14: 

I am writing to you, little children, because your sins have been forgiven you for His name’s sake. I am writing to you, fathers, because you know Him who has been from the beginning. I am writing to you, young men, because you have overcome the evil one. I have written to you, children, because you know the Father. I have written to you, fathers, because you know Him who has been from the beginning. I have written to you, young men, because you are strong and the word of God abides in you, and you have overcome the evil one. 

Similar to Paul, the Apostle John uses the analogy of physical maturation to depict spiritual growth (although the Greek words to characterize these levels of growth are different). Importantly, what distinguishes the three levels of spiritual maturity between the child, the young man, and the father in John’s first letter is this: the young man and the father differ from the child in that they have overcome the evil one. Much more can be learned from this passage, but in relation to this study and this subpoint, what this similarly illustrates is that the spiritually mature believer can and will discern spiritual truth from error, whereas the infant does not. In other words, babes can get caught in the web of false doctrine or religion. The spiritually mature, on the other hand, have come to grips with the truth of 1 Peter 5:8: 

Be of sober spirit, be on the alert. Your adversary, the devil, prowls around like a roaring lion, seeking someone to devour. 

Satan thrives at sidetracking young believers into false religious systems that (to the spiritually less discerning) seem to be like biblical Christianity. But the spiritual adult can ascertain true saving faith from false religions and cults as is implied by the third passage in the original listing of passages: 

As a result [they] are no longer … children, tossed here and there by waves and carried about by every wind of doctrine, by the trickery of men, by craftiness in deceitful scheming (Ephesians 4:14). 

The child in the faith tends to go with the flow (the wrong flow), i.e., tossed here and there by waves, which may or may not be doctrinal in nature. This verse could refer to following others who cause schisms in the body of Christ. Furthermore, they are doctrinally deceived. Notice Paul says in this regard, every wind of doctrine, i.e., they cannot discern correct doctrine as supported by the Word of God. They lack knowledge of the Word. All they know is that “Jesus loves me, and I know my sins are forgiven.” It is not uncommon for those at this level of maturity, i.e., babes in Christ, to attend a religious institution that teaches salvation is attained in some other fashion than by faith alone in Christ alone. (As I often have said in our Bible studies, a common thread among all false religions is an unbiblical understanding of the person and work of Christ, often combined with extra-biblical revelation of some sort.) As spiritual infants, they lack the ability to discern error from truth. They lack training in the Word of God. 

At the risk of sounding arrogant or self-righteous, I will say that most believers today in the American Church are spiritual infants. Most are grossly under-taught in the Word of God due to the impact of the seeker-sensitive movement in many churches. Accordingly, they are headed for heaven, but in the meantime, their usage by God here on earth is quite limited. 

Now think of this unfortunate phenomenon as it relates to public servants who desire higher office: in few circumstances does a president or a king appoint an infant to an important task. First, the would-be servant must grow up and come to know the king personally and intimately, earning his trust in maturity by living in accordance with his principles. Only then could that one possibly think he or she might be appointed to an important position. In a similar sense, do not expect God to appoint you to a higher level of service prior to maturing in your relationship with Him. 

B. ADULTS UNIFY THE BODY 

Until we all attain to the unity of the faith, and of the knowledge of the Son of God, to a mature man … (Ephesians 4:13). 

In this Ephesians passage, again contrasting teleion with nepios, yet another characteristic of a mature believer comes to light. Mature believers are critically sensitive to the unity of the body of Christ. They hold unity as a high priority because, for one reason, the corporate unity of the body of Christ is the strongest form of evangelism to the secular world. Regarding this point, Jesus said this to God the Father in John 17:21: 

“That they may all be one; even as You, Father, are in Me and I in You, that they also may be in Us, so that the world may believe that You sent Me.” 

The unity of the body is extremely important to those who are mature in Christ, and they will avoid disrupting it. In contrast, the spiritually immature, as previously seen, are characterized by jealousy, which leads to strife, which leads to disunity. 

C. ADULTS DISPLAY CHRISTLIKENESS AND ARE GROWING 

To the measure of the stature which belongs to the fullness of Christ (Ephesians 4:13b). 

As the believer grows closer to Christ through prayer and obedience to His Word, he becomes more and more like the One Who saved him. This ongoing process is aided by the indwelling Holy Spirit. It should be noted again that perfection in Christlike behavior will never be fully attained in this life; not until we go to be with our Savior (glorification) is perfection achieved. It follows then that we must be gracious and patient with others in agapé love—not self-righteously thinking we have a lock on orthopraxy and orthodoxy. Interestingly, Paul uses the word mature or complete (teleios) in Colossians to explain the unending role and goal of the pastor-teacher in this sanctifying process: 

We proclaim Him, admonishing every man and teaching every man with all wisdom, so that we may present every man complete in Christ (Colossians 1:28). 

Continued maturation is a sign of adulthood; moving toward completeness is normal for the Christian life. Paul said to the Philippians (1:6): 

For I am confident of this very thing, that He who began a good work in you will perfect it until the day of Christ Jesus. 

It goes without saying that those who are maturing are also characterized by humility when they discover that they are out of sorts with Scripture. 

D. ADULTS KNOW DOCTRINE AND ARE MATURE THINKERS 

Brethren, do not be children in your thinking; yet in evil be infants, but in your thinking be mature (1 Corinthians 14:20). 

This passage is from the final verse listed in the opening contrasting Scriptures. The context of this passage from Paul’s first epistle to the Corinthians has to do with the issue of spiritual gifts, but in a broader sense of application, it relates to this week’s subject matter. Specifically, Paul is addressing the Corinthian believers—and by extension, all believers—with the admonition to be mature in their thinking. 

Mature believers are characterized by mature thinking: they possess an ability to understand the principles of Scripture and reason out from them, making sound, principle-based applications of the truths therein, not only in their personal lives but also in their policy formation. All their decisions will accurately reflect the principles and precepts of His revelation via Scripture. Mature believers are not disconnected from scriptural truth and application in any area of their lives; that is to say, mature believers have integrity with the Word of God. 

Mature-in-Christ public servants are biblically based thinkers who reason from the epistemological basis and everlasting authority of God’s Word. 

Proverbs 2:6 states this same idea: For the Lord gives wisdom; from His mouth come knowledge and understanding. Continuing with Proverbs 7:4, Say to wisdom, “You are my sister,” and call understanding your intimate friend. Therefore, unlike in infants, a true knowledge and deep understanding about the fundamental, foundational issues of life is characteristic of mature, spiritual adults. How our nation needs more public servants who are not only trained but also discerning, unifying, growing, mature thinkers! They are born from an intense, Holy Spirit-given desire to grow up in Christ. 

IV. SUMMARY 

Are you a spiritual child or adult? Which list best characterizes you? 

My prayer is that this study will help you in your quest for spiritual maturity relative to these respective, definitive passages on the subject. In your examination of these questions, remember the words of Benjamin Rush, a signer of the Declaration of Independence, to his son: 

“Be sober and vigilant. Remember at all times that while you are seeing the world, the world will see you. Recollect further that you are always under the eye of the Supreme Being.”¹ 

May God bless you as you ponder and measure yourself against this scriptural plumb line.  

 

1. Dorie Lawson, Posterity: Letters of Great Americans to Their Children (New York: First Anchor Books, 2004), 268.