15 but, speaking the truth in love, may grow up in all things into Him who is the head—Christ—
Full understanding and appropriation of who and what Jesus is and did shows our level of maturity.
into Him [Christ]
Paul portrayed the church in the image of the head and body. The idea of “head” in Greek literature was different than our idea in the twenty-first century. The “head” here is not like the head of an organization or government. The New Testament uses “head” in the sense of source. In this context, (1) Christ is the source for growth, (2) the body grows into Christ, and (3) each part does its work. The body responds to the head and His provision.
Knowing and experiencing Christ is the aim of spiritual growth (4:13). The word “into” means with a view to, which carries the idea here of growing into resemblance of Christ. He is the object or goal toward which we grow. Growth moves us closer to the standard of who and what Christ is. We conform to our Head because we have an intimate union with Him.
In verse 15 we grow up “into Him” and in verse 16 we grow from or out of Him. “Out of” Him pertains to source. The body derives its strength from its ultimate and vital source for growth.
who is the head—Christ—
Paul used the analogy of the human head and body in the passage to illustrate the Christian’s relation to the Lord. The body gets its direction from the Head; the church obtains guidance from Christ. As the Head, Christ is the source for all functions of the body and its growth (Co 2:19). Christ is the source of growth both for the individual and for the corporate body.
Growth of the body has Christ as the goal.
A mature Christian and church have a full understanding and appropriation of Christ as his or her goal. It is not enough to superficially understand who and what He is. This is God’s goal for both the individual and the corporate church. The more we know Him, the greater we appreciate Him and live like Him.