True believers are not self-made people. They have come to “fullness” in Christ. This means that their purpose for living, their power to love, and everything good they do comes from Christ, and they willingly give Him credit for it. Be suspicious of any so called believer who does not make Jesus the center of everything he does.
For in Christ all the fullness of the Deity lives in bodily form, 10 and in Christ you have been brought to fullness. He is the head over every power and authority. (Colossians 2:9-10)