Conformist, or as I like to say "traditionalists", those that still believe in eternal damnation, a hell and heaven, will use the passage in Corinthians where Paul, says "all will be vivified in Christ", to say that he means that only those who  have "given" themselves, or dcelared to be followers of the Christ..only Christians will be vivified.

But that was not his meaning.

When Paul said ALL will be vivified, he meant ALL humankind from Adam through the return of Christ, because that is what he was told by the Spirit of God!

Keeping in mind, that there will be those who will experience the "second death", prior to being vivified.

This will occur to all humans, regardless of their religious belief..Christians don't belong to a special category in this matter.

 True, "believers'",  the Ecclesia those of the body of Christ enjoy a special "place", only because we know that this will happen, whereas so many others   are either unaware or refuse to believe it.

When he said "in Christ", he means that only due to Jesus Christ's  sacrifice that God has declared all sins are abolished, the last being "death", and ALL mankind will benefit through vivication..paulnbob