Adam Clarke on 1 Corinthians 15:18

They also which are fallen asleep - All those who, either by martyrdom or natural death, have departed in the faith of our Lord Jesus Christ, are perished; their hope was without foundation, and their faith had not reason and truth for its object. Their bodies are dissolved in the earth, finally decomposed and destroyed, notwithstanding the promise of Christ to such, that he would raise them up at the last day. See Joh 5:25, Joh 5:28, Joh 5:29; Joh 11:25, Joh 11:26, etc.