“By which also ye are saved, if ye keep in memory what I preached unto you, unless ye have believed in vain.”
King James Version (KJV)
15:2 Ye are saved, if ye hold fast - Your salvation is begun, and will be perfected, if ye continue in the faith. Unless ye have believed in vain - Unless indeed your faith was only a delusion.
1Co 15:2 By which also ye are saved. Are in a saved state unless you have forgotten the gospel preached and departed from it; that is, unless ye have believed in vain, which he shows would be the case if there was no resurrection. Observe the tact with which he first presents facts conceded by all the disciples, and upon these builds an impregnable argument. He next states those facts.