It is a faithful saying: see the notes on 1 Timothy 1:15, and 1 Timothy 4:9, where we had the same phrase. For if we be dead with him: we are said to be dead with Christ two ways:
1. By our dying to sin, as he died for sin, Romans 6:5.
2. By our suffering in testimony of the truth, 2 Corinthians 4:10, which is that being dead with him which is here mentioned. We shall also live with him: there is also a twofold living with him, by a rising again to a newness of life, Romans 6:5, and hereafter in glory, which latter is here intended.