Who died for us, that, whether we wake or sleep, we should live together with him.
Dead for us, х huper (G5228)] - 'in our behalf.' So that we need have no doubt of the certainty of our salvation, since Christ has for us satisfied all the demands of justice against us.
Whether we wake or sleep - whether we be found at Christ's coming alive, or in our graves.
Together with him - rather, 'all of us together should live with Him:' the living not preceding the dead in glorification at His coming (1 Thessalonians 4:13; Romans 14:8).