During the days of the Roman Empire the Jews had charged the Christians that Christ had been raised from the dead by sorcery.Pionius countered the Jewish claim by pointing out that Samuel had NOT been raised by the witch of Endor, but rather that a demon had taken his form to appear.
If sorcery could not raise Samuel from the dead, it surely could not have raised Christ-hence Christ was raised from the dead by God.
2 things of note here:
1) Notice the Jews didn't claim Christ wasn't raised from the dead-rather they accredited it to sorcery.
2) Not all early Christians had bought into the myth of the immortality of the soul yet.
For the living know that they shall die: but the dead know not any thing,...
Ecclesiastes 9:5
