1 Corinthians 15:6, 17, 42

After that He appeared to more than five hundred brothers and sisters at one time, the majority of whom are still alive, but some have fallen asleep [in death].

and if Christ has not been raised, your faith is worthless and powerless [mere delusion]; you are still in your sins [and under the control and penalty of sin].

So it is with the resurrection of the dead. The [human] body that is sown is perishable and mortal, it is raised imperishable and immortal. [Dan 12:3]