1 Peter 3:19
18 Because Christ also suffered once for sins, the just for the unjust, to bring you to God, by being put to death in the flesh but by being made alive in the spirit. 19 In it he went and preached to the spirits in prison, 20 after they were disobedient long ago when God patiently waited in the days of Noah as an ark was being constructed. In the ark a few, that is eight souls, were delivered through water.
Origen Contra Celsum 2.43
Against CelsusCelsus next addresses to us the following remark: You will not, I suppose, say of him, that, after failing to gain over those who were in this world, he went to Hades to gain over those who were there. But whether he like it or not, we assert that not only while Jesus was in the body did He win over not a few persons merely, but so great a number, that a conspiracy was formed against Him on account of the multitude of His followers; but also, that when He became a soul, without the covering of the body, He dwelt among those souls which were without bodily covering, converting such of them as were willing to Himself, or those whom He saw, for reasons known to Him alone, to be better adapted to such a course.
Notes and References
"... Origen, a contemporary of Clement, understood 1 Peter 3:18-22 in a similarly positive manner. For Origen there was still hope for the people destroyed by God’s judgement in the Flood. Furthermore, Origen seems to allude to 1 Peter 3:19 in countering Celsus’ accusation that Christ’s descent and preaching was the consequence of the failure of his earthly preaching ministry. Origen emphasizes that this aspect to Christ’s ministry was intentional in order to win converts from among the souls of the dead individuals ..."
Rensburg, Fika J. and D. N. Campbell A History of the Interpretation of 1 Peter 3:18-22 (pp. 73-96) Acta Patristica et Byzantina 19(1), 2008