And I, brethren, could not speak to you as to spiritual people but as to carnal, as to babes in Christ. I fed you with milk and not with solid food; for until now you were not able to receive it, and even now you are still not able; for you are still carnal.

1 Corinthians 3:1-3 (NKJV)

Be childlike, but not childish.

The Apostle Paul was chastising the Corinthian church for its lack of spiritual growth. Although they have joyfully received the gospel, they have never fully matured in their understanding of it. Because of their spiritual immaturity, the Corinthians exercised poor judgement and made poor decisions.

The root cause of spiritual immaturity is a diet problem.

Instead of eating solid food like mature adults, the Corinthians continued to drink milk like babies. Because of their slow growth, Paul must re-teach them the fundamental truths of the gospel. There is nothing wrong with learning the fundamentals, but if we want to grow a healthy spiritual life, we must go beyond our basic understanding of the gospel.

You are stagnant if you are not growing!

Spiritual complacency and self-satisfaction are fostered by stagnation. It's when you appear spiritual on the outside but are quite the opposite on the inside. What's on the inside will eventually come out and reveal how deeply rooted you are in Christ. This is why Paul referred to the Corinthians as carnal babies. They were more concerned with satisfying their fleshy desires than with growing in their faith and knowledge of Christ.

Paul, on the other hand, did not give up on the Corinthians.

He hopes they will learn from their mistakes and mature. He assured the Corinthians that, despite their carnality, God is still working on them through the power of the gospel. Paul was rewarded for his labour of love (cf.2 Corinthians 7:9). When the Corinthians grew in their knowledge of Christ, they did not just regret what they had done, but they repented of their ways. Personal condemnation and self-effort will never result in spiritual growth and maturity. A childlike faith in Jesus, on the other hand, will cause you to blossom and bear fruit in the Lord.