Romans 6:3 - Matthew Poole's English Annotations on the Holy Bible

Know ye not? q.d. This is a truth which you ought not to be ignorant of and which confirms what I say. Baptized into Jesus Christ: to be baptized into Christ, is either to be baptized in the name of Christ; see Acts 10:48, and Acts 19:5; or else it is, incorporated, ingrafted, or planted into Christ, and so to be made members of his mystical body by baptism. Baptized into his death: to be baptized into the death of Christ, is to have fellowship with him in his death, or to have the efficacy of his death sealed up to us; and that is the blessed privilege of as many as are baptized or planted into Christ; they are not only partakers of the merit of his death for justification, but of the efficacy of his death for mortification. See a parallel place, Galatians 3:27.