'Mature' in the Bible

Yet when we are among mature believers we do speak words of wisdom; a wisdom not belonging, however, to the present age nor to the leaders of the present age who are soon to pass away.

till we all of us arrive at oneness in faith and in the knowledge of the Son of God, and at mature manhood and the stature of full-grown men in Christ.

Therefore let all of us who are mature believers cherish these thoughts; and if in any respect you think differently, that also God will make clear to you.

Therefore leaving elementary instruction about the Christ, let us advance to mature manhood and not be continually re-laying a foundation of repentance from lifeless works and of faith in God,