Matthew Poole and continuators on 1 Corinthians 15:18

18 Then they also who are fallen asleep in Christ, are perished .

Some think that the term in Christ in this Text, is of the same significancy with for the sake of Christ, which would restrain it to Martyrs; but I know no reason for that, because what is said, it true of all; for it is plain, from what was said before, that if Christ be not risen from the dead, all that dye must dye in their fins, there being no object for their Faith to work or lay hold upon. The door of Salvation remaineth as fast shut as ever, so as those whom they looked upon as being asleep in Christ, must necessarily perish, if Christ be not risen; there is no Forerunner entred into the Heavens for us.