I was reading about persecutions by Christians and was wondering if the persecutors justified their violence with passages of the bible and how they reconciled that with the teachings of Jesus.

In particular, on this website I read about Calvin: "So entirely was he in favour of persecuting measures, that he wrote a treatise in defence of them, maintaining the lawfulness of putting heretics to death."

I'm not asking about the general view of Calvin regarding capital punishment or his philosophical, civil or criminal law thoughts on it but specifically I was wondering how he reconciled supporting killing of people with other religious views with the teachings of Jesus or the New Testament. Would Jesus, according to Calvin, have supported the killing of heretics?