What does the Bible say about growing up in Christ?

In 1 Corinthians 13:11, Paul contrasts the speech and understanding of a child with that of a man, emphasizing that spiritual maturity involves putting away childish things. This transformation occurs when a person becomes a new creation in Christ, signifying a fundamental change in their nature and way of thinking. Similarly, Galatians 4 speaks of the difference between being a child under the elements of the world and becoming an heir, highlighting the believer's growth into the maturity granted by grace.