i.e. If we have fellowship with Christ in his death, we have reason to believe we shall have fellowship with him also in his resurrection and life: see Romans 6:5. Though everlasting be not excluded, yet a spiritual life is principally intended; we shall so live with Christ, as no more to return to dead works. The next words show this to be the sense.
Related Commentaries of Romans 6:8
Romans 6:8
8 Now if we be dead with Christ, we believe that we shall also live with him: