Eternal sin
Thomas Aquinas lists, or has responded to, six sins that supposedly go against the Holy Spirit:
Thomas Aquinas explains that the unforgivability of blasphemy against the Holy Spirit means that it removes the entrance to these means of salvation; however, it cannot hinder God in taking away this obstacle by way of a miracle.
David Flusser
Flusser pursued his research at a time when many Jews blamed Christianity for Nazism. During his trial in Israel, the Gestapo officer Adolf Eichmann refused to take an oath on the New Testament, insisting he would swear only "in the name of God." Flusser commented in an editorial in the "Jerusalem Post": "I do not know who is the God in whose name Eichmann swore, but I am certain that it is neither the God of Israel nor the God of the Christian church. It should now become clear to the strongest Jewish opponents of Christianity that Christianity "per se" imposes limitations, and that the greatest crime against our people was not committed in the name of the Christian faith".