B.J. Oropeza on baptism in Galatians 3:27

εις Χριστον in Galatians 3:27 appears to be an abbreviation form for εις το ονομα του κυριου Ιησου Χριστου. The passage likely refers to an incorporation into the body of Christ at baptism which is depicted in terms of "putting on" (ενδυσασθαι) Christ as one puts on a garment (cf. 1 Cor. 12:13) . . . In the final analysis Paul may have understood the phrase "in the name of Jesus" not as a magical or semi-magical pronouncement as perhaps some of the Corinthians did; rather, he saw it in terms of conversion-initiation in which the baptised confesses the name of the Lord Jesus Christ is bound in union with his person. At baptism there is a strong sense of belonging to Christ and becoming a member in the elect and consolidated body of Christ. Baptism in the name of Jesus thus incorporates a convert into a community of members who are seen as the body of the name which that community represents. The stress on baptism rests not so much on immersion in water as it does on the confession of one's faith in Christ and the immersion in the Spirit, both occurring presumably at one's baptism (1 Cor. 6:11; 12:13; cf. Tit. 3:5; Acts 2:38f; 9:17-18). (B.J. Oropeza, Paul and Apostasy: Eschatology, Perseverance, and Falling Away in the Corinthian Congregation [Eugene, Oreg.: Wipf & Stock, 2007], 85, 89-90)