Adam Clarke's Commentary on the Bible

Verse 27 (Galatians 3:27)

As many of you as have been baptized into Christ - All of you who have believed in Christ as the promised Messiah, and received baptism as a public proof that ye had received Christ as your Lord and Savior, have put on Christ - have received his Spirit, and entered into his interests, and copied his manners. To put on, or to be clothed with one, is to assume the person and character of that one; and they who do so are bound to act his part, and to sustain the character which they have assumed. The profession of Christianity is an assumption of the character of Christ; he has left us an example that we should follow his steps, and we should, as Christians, have that mind in us which was in him. See the notes on Romans 6:3 , Romans 6:4 ; and especially those on Romans 13:14 ; (note), where this phrase is farther explained.

- Adam Clarke's Commentary on the Bible