The correct answer is: The harrowing of hell.
Indeed, the main principle of Christianity is that the only way to be saved is by accepting Jesus Christ as one’s Savior. However, the problem of good people both Jewish and Gentile, who had lived and died long before Jesus came to earth remained. If they were good people, and especially if they were monotheistic believers in God, like Adam, Moses and Abraham how would it be fair for God to let them in hell for eternity? According to several verses in the New Testament, when Jesus was crucified and died, he went down to hell and rescued all these people.
A notable one is Peter 3:19-20: “19 in which also he went and made a proclamation to the spirits in prison, 20 who in former times did not obey, when God waited patiently in the days of Noah, during the building of the ark, in which a few, that is, eight persons, were saved through water.”
