Origen's response:
"We assert that Jesus not only converted no small number of persons while he was in the body . . . but also, that when he became a spirit, without the covering of the body, he dwelt among those spirits which were without bodily covering, converting such of them as were willing to Himself."
(Origen, Against Celsus II'' 43, in PG 11:864-65)

Celsus (Greek: Κέλσος) was a 2nd century Greek philosopher and opponent of Christianity. He is known to us mainly through the reputation of his literary work, The True Word (Account, Doctrine or Discourse) (Λόγος 'AληΘής), almost entirely reproduced in excerpts by Origen in his counter-polemic Contra Celsum of 248, 70 or 80 years after Celsus wrote.