Maturity (13): Paul plainly states the purpose of ministry. Each member is to do the work of service, the building up of the body of Christ, with the aim that the church as a whole (“we all”) would attain to the fullness of Christ. This is spiritual maturity of the church where the entire community reflects the full likeness to her Lord. Doctrinal soundness is vitally important in this, but this is no mere head-knowledge. We are to have a church-wide understanding of who Christ is, which is to conform us to His character and godliness.
Growth (14-16): Paul further fleshes out our purpose. First, we are to be well-guarded. Protection from false teaching is vital as it keeps us from a false Christ. This staves off wrong ideas about our Savior and Lord and what we are to be in His likeness. Pure knowledge of the Lord enables growth, which is the second purpose. We are to grow up into Christ in all that He is (“in all aspects”). As He is full of grace and truth, compassionate, holy, full of self-sacrifice, humble and gentle, and as He loved, prayed to, trusted, obeyed the Father, and as He loved the lost and sought after their salvation, so God wants us to be as His church. We will never reach full Christ-likeness in this life. But when each member plays their part (“in their own measure”) to manifest Christ to one another and beyond, we can collectively manifest His fullness.
 “For the work of service” and “to the building up” are parallel and appositional. They both begin with the preposition eis (εἰς). The church is prepared for the work of service, which is the building up of the body.
 Sound doctrine and godliness go hand in hand (cf. 1 Tim. 6:3-4; Titus 2:1ff.; 1 Tim. 3:16). We are to know Christ for the purpose of conformity to Him (2 Cor. 3:18) and growing in godliness (2 Pet. 1:8).
 “We are no longer to be” and “we are to grow up” are parallel verbs that follow “so that” (NASB’s footnote).
 John 1:14; Matt. 9:36; Heb. 7:26; John 10:11; Gal. 2:20; Matt. 11:29; John 14:31; Heb. 5:7; Phil. 2:8; Lk. 19:10.
 “Proper working” is literally “working in measure” (NASB footnote). This harkens back to 4:7 where Christ gave to each of us a particular expression of favor measured out individually.