Ephesians describes maturity as growth toward ‘the measure of the stature of the fullness of Christ’ — a process where the Word of God does the planting and watering, but God alone gives the growth. Faith comes by hearing, and hearing through the word of Christ, so Scripture itself is the foundation any believer matures upon.
Jesus calls His disciples to become like children in humility and trust, receiving the kingdom the way a child receives what is given. But Paul warns against the opposite: being tossed about like children by every wind of doctrine. The sermon closes by asking whether believers mature themselves or are matured by God, pointing to Moses’ call in Deuteronomy to choose life, and to the Holy Spirit as the one present to counsel, help, and sanctify along the way.