The writer of Hebrews gives one of the most uncomfortable rebukes in the New Testament: “For though by this time you ought to be teachers, you need someone to teach you again the basic principles of the oracles of God. You need milk, not solid food, for everyone who lives on milk is unskilled in the word of righteousness, since he is a child. But solid food is for the mature, for those who have their powers of discernment trained by constant practice to distinguish good from evil” (Hebrews 5:12–14).
The rebuke is not about intelligence. It is about time. These believers had been Christians long enough to be teaching others. Instead, they still needed the basics. Spiritual maturity, Hebrews says, is not measured by how long you have been a Christian. It is measured by how far you have grown. Time in the faith is not the same as growth in the faith. A person can be a Christian for thirty years and still be an infant — or a Christian for three years and be remarkably mature. The difference is not the calendar. It is the practice.
From Milk to Solid Food: The Growth Pattern
The New Testament uses the language of human development to describe spiritual growth. New believers are “newborn infants” who “long for the pure spiritual milk” (1 Peter 2:2). That is normal and good. Infants need milk. No one rebukes a baby for drinking milk. The problem comes when a person who should be eating solid food still wants only milk — when growth stalls.
Paul used the same image with the Corinthians: “I fed you with milk, not solid food, for you were not ready for it. And even now you are not yet ready, for you are still of the flesh” (1 Corinthians 3:2–3). The evidence of their immaturity was not ignorance. It was jealousy, strife, and division. They were fighting over which leader to follow. Paul’s diagnosis: spiritual immaturity shows up in relationships before it shows up in theology. The infant Christian is marked by self-centeredness, quarreling, and the need to be the center of attention. The mature Christian is marked by love, peace, and the ability to handle disagreement without dividing.
Ephesians 4 gives the goal of growth: “until we all attain to the unity of the faith and of the knowledge of the Son of God, to mature manhood, to the measure of the stature of the fullness of Christ” (Ephesians 4:13). The standard is not “better than other Christians.” The standard is Christ Himself. Maturity means becoming like Jesus — in character, in love, in wisdom, in obedience, in mission. It is a lifelong process, and no one arrives in this life. But everyone is called to be moving.
The Marks of Maturity
What does a mature Christian actually look like? The Bible gives a consistent portrait across many passages, and it is strikingly different from what many people assume.
First, discernment. “Solid food is for the mature, for those who have their powers of discernment trained by constant practice to distinguish good from evil” (Hebrews 5:14). Maturity is not knowing more facts. It is having trained senses — the ability to recognize truth from error, wisdom from folly, good from evil — through practice. Discernment is a skill, built by repeatedly applying Scripture to real decisions, making mistakes, repenting, and learning. The mature believer does not need someone else to decide everything for them. They have learned to think biblically.
Second, stability. Paul says the goal of growth is “so that we may no longer be children, tossed to and fro by the waves and carried about by every wind of doctrine” (Ephesians 4:14). Immature believers chase every new teaching, every charismatic personality, every trending idea. Mature believers are anchored. They know what they believe, why they believe it, and they are not easily shaken by novelty or pressure.
Third, self-control. The fruit of the Spirit — love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, self-control (Galatians 5:22–23) — is the Bible’s primary maturity test. Notice what is not on the list: knowledge, eloquence, charisma, success, or platform size. The Spirit’s fruit is character. A mature Christian controls their tongue (James 3:2), manages their anger, resists temptation, and keeps their promises. Giftedness without character is immaturity with a microphone.
Fourth, love for others. “Whoever loves his brother abides in the light” (1 John 2:10). John makes love the decisive test: “By this we know that we have passed from death to life, because we love the brothers” (1 John 3:14). Maturity is measured by how you treat people — especially difficult people. The mature believer forgives quickly, serves quietly, gives generously, and bears with others’ faults.
Fifth, teachability and reproduction. “By this time you ought to be teachers” (Hebrews 5:12). Maturity is not just receiving; it is giving. The mature believer can explain the faith to others, disciple younger Christians, and pass on what they have learned. If your faith has never helped anyone else grow, it has not yet matured.
Sixth, endurance in suffering. James says, “The testing of your faith produces steadfastness. And let steadfastness have its full effect, that you may be perfect and complete, lacking in nothing” (James 1:3–4). Trials are not interruptions to growth. They are the mechanism of growth. The mature believer has been through hard things and come out steadier, not bitterer.
How Growth Happens
Spiritual maturity is not automatic. It does not come from merely attending church, reading Christian books, or accumulating years. The Bible describes growth as a cooperative process: God works, and believers work. “Work out your own salvation with fear and trembling, for it is God who works in you, both to will and to work for his good pleasure” (Philippians 2:12–13). God supplies the power. Believers supply the practice.
The primary means of growth is the Word. “All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness, that the man of God may be complete” (2 Timothy 3:16–17). The Bible is not just information; it is training. Reading it daily, meditating on it, memorizing it, and obeying it is the spiritual equivalent of eating, exercising, and training. A Christian who does not engage Scripture will not grow, any more than a body that does not eat will grow.
The second means is prayer. Prayer is not just asking God for things. It is communion — the relationship in which character is formed. The mature believer prays honestly, listens, confesses, and intercedes. Prayer keeps the heart soft toward God.
The third means is community. “Iron sharpens iron, and one man sharpens another” (Proverbs 27:17). Growth happens in relationships — in small groups, in friendships, in serving alongside others, in being corrected by people who love you. Lone-wolf Christianity produces stunted Christians. The church is the gym where maturity is built.
The fourth means is suffering and discipline. “God disciplines us for our good, that we may share his holiness” (Hebrews 12:10). Trials, corrections, failures, and hardships are God’s tools for shaping character. The mature believer does not resent discipline. They receive it as the work of a Father who loves them too much to leave them as they are.
The fifth means is obedience in small things. Growth is not built on dramatic moments. It is built on daily faithfulness: telling the truth when a lie would be easier, forgiving when resentment feels justified, serving when no one notices, giving when it costs. Maturity is a thousand small obediences, compounded over a lifetime.
The Honest Truth About Growing
Growth is slow. It is uneven. It includes setbacks, regressions, and seasons when you feel like you are going backward. David, Peter, and Abraham all had seasons of failure after seasons of faithfulness. Maturity is not a straight line. It is a long walk with a faithful God who does not give up on slow growers.
Growth is also never finished. Paul, near the end of his life, wrote, “Not that I have already obtained this or am already perfect, but I press on to make it my own, because Christ Jesus has made me his own” (Philippians 3:12). If the apostle Paul had not arrived, neither have you. The mature believer is not the one who thinks they have arrived. It is the one who knows they have not — and keeps pressing on.
The question is not “Are you mature?” The question is “Are you growing?” Are you more like Christ this year than last year? Are you more patient, more loving, more discerning, more stable? If the answer is yes — even a little — then growth is happening. And the God who began the good work in you will bring it to completion (Philippians 1:6). For a survey of how Christian traditions have described spiritual growth and formation, see the Wikipedia article on spiritual formation.
