Ephesians 4:14-16

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, from whom the whole body, being fitted and held together by what every joint supplies, according to the proper working of each individual part, causes the growth of the body for the building up of itself in love.

As a result of the foundation laid be the four groups mentioned in the previous verses believers will not be like children, easily persuaded and confused, jumping from one opinion to the next, hopping on the newest spiritual bandwagon, and driven by gusting winds of false doctrine. Rather we will know the truth and speak it in love. Immature people often speak the truth without love, pounding people with what we see as their errors, or love without speaking the truth, thinking that we are sparing people pain when we are contributing to it by our silence. Christ fits the boy together with the gifts needed to benefit the other members of the body and lead us all into maturity. We belong together, and each person’s contribution is significant.

When the whole body is building itself up in corporate likeness to the maturity of Christ, the effect is that the members of the body in that process become discerning and perceptive and stable. They have their faculties trained to see through the subtle, manipulative use of language that tricks people into affirming things that are not true or right.

-John Piper