Christ said that He will say to false prophets, “I never knew you!” There is no hint that any of those to whom He refers in Matthew:7:21–23 had once been saved and then lost their salvation, which surely must be the case if the “falling away” doctrine is correct. Why didn’t the Lord say that they’d fallen from grace, rather than that they’d never been His—or at least include some people in that category? In fact, He makes no such statement.
"Many will say to me in that day, Lord, Lord, have we not prophesied in thy name? and in thy name have cast out devils? and in thy name done many wonderful works? And then will I profess unto them, I never knew you: depart from me, ye that work iniquity."