'Develop' in the Bible

until we all reach oneness in the faith and in the knowledge of the Son of God, [growing spiritually] to become a mature believer, reaching to the measure of the fullness of Christ [manifesting His spiritual completeness and exercising our spiritual gifts in unity].

and He must not be a new convert, so that he will not [behave stupidly and] become conceited [by appointment to this high office] and fall into the [same] condemnation incurred by the devil [for his arrogance and pride].

For this very reason, applying your diligence [to the divine promises, make every effort] in [exercising] your faith to, develop moral excellence, and in moral excellence, knowledge (insight, understanding),

and in your knowledge, self-control, and in your self-control, steadfastness, and in your steadfastness, godliness,

and in your godliness, brotherly affection, and in your brotherly affection, [develop Christian] love [that is, learn to unselfishly seek the best for others and to do things for their benefit].