‘Who died for us, that whether we wake or sleep we should live together with him.'
Having stated the fact of salvation Paul now declares the basis. It is because our Lord Jesus Christ died for us that salvation is possible. The very fact of his mentioning the death of Christ here demonstrates that he knew of no other way by which a man could be saved. And the result of that death is that when we believe in Him we are put into a position where it does not matter whether we ‘fall asleep in Christ' or are found still ‘awake'. In either case, at His coming, we begin to live together with Him, we begin to experience His life as the spiritual life-giver (John 5:21; John 5:25; John 5:29).
Interestingly the verbs are the same as in 1 Thessalonians 5:6 but the meaning is totally different. There sleeping and being awake were referring to a moral state. Here it refers to having died or being alive. It answers the question posed in 1 Thessalonians 4:13. It is true that the word for the sleep of Christians in 1 Thessalonians 4:13 is different from here but there is no suggestion elsewhere in Thessalonians that some Christians will be sleeping morally in relation to His coming, and 1 Thessalonians 5:5 contrasts the ‘sons of light' with those ‘of darkness', while 1 Thessalonians 5:6 parallels those who are ‘awake' with those who ‘sleep'. The clear implication is that the sons of light are those who are awake, and those who sleep are sons of darkness. He is hardly likely here therefore to have been changing that picture when a simpler explanation is at hand.
While Paul no doubt knew that some Christians were not as watchful as they should be, it was not something he would mildly have accepted. The question is, can a person be a Christian and not at all watchful? The answer must be no.