Ephesians 4:13-15
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; but speaking the truth in love, we are to grow up in all aspects into Him who is the head, even Christ,
Colossians 2:6-7
Therefore as you have received Christ Jesus the Lord, so walk in Him, having been firmly rooted and now being built up in Him and established in your faith, just as you were instructed, and overflowing with gratitude.
Romans 15:14
And concerning you, my brethren, I myself also am convinced that you yourselves are full of goodness, filled with all knowledge and able also to admonish one another.
1 Corinthians 2:6
Yet we do speak wisdom among those who are mature; a wisdom, however, not of this age nor of the rulers of this age, who are passing away;
1 Corinthians 14:20
Brethren, do not be children in your thinking; yet in evil be infants, but in your thinking be mature.
1 Corinthians 3:1-3
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?
https://bible.knowing-jesus.com/topics/Maturity,-Spiritual