1 Corinthians 15:13

But if there be no resurrection of the dead, then is Christ not risen (KJV)

Then: Paul finishes the thought with its opposing logic. If resurrection were impossible, then Christ did not rise .... and the Corinthians are not saved. Everyone still bears the burdens of sin. That presents a conundrum of major proportion - besides they already know they possess the gifts of the Spirit, the Comforter who came to each after the resurrection. So even though it might look like someone could deny resurrection, Christ's followers cannot. They know the Truth.

Now: Believers still reason the same way.