References
Henry Charles Lea, History of Inquisition of Middle Ages vol 1, (1888) [New York: Harbor Press, 1955 ]
http://www.pinn.net/~sunshine/gage/mjg.html
"They knew that Christ had said, "I am not come to destroy the law but to fulfill" (Matt. 5:17). They also knew from Holy Writ that Jehovah was a God delighting in the extermination of his enemies. They read how Saul, the chosen King of Israel, had been divinely punished for sparing Agag the Amalek, and how the prophet Samuel had hewn him in pieces; how the wholesale slaughter of the unbelieving Canaanites had been ruthlessly commanded and enforced; how Elijah had been commended for slaying four hundred and fifty priests of Baal; and they could not conceive how mercy to those who rejected the true faith could be aught but disobedience to God. Moreover, Jehovah was a God who was only to be placated by the continual sacrifice of victims. The very doctrine of the Atonement assumed that the human race could only be rendered eligible to salvation by the most awful sacrifice that the human mind could conceive -- that of one of the members of the Trinity. The Christian worshipped a God who had subjected himself to the most painful and humiliating of sacrifices, and the salvation of souls was dependent on the daily repetition of this sacrifice in the mass, throughout Christendom. To minds moulded in such a belief, it might well seem that the extremity of punishment inflicted on the enemies of the Church of God was nothing in itself, and that it was an acceptable offering to him who had commanded that neither age nor sex should be spared in the land of Canaan.1"
Henry Charles Lea, History of Inquisition of Middle Ages vol 1, (first edition 1888) [New York: Harbor Press, 1955]
The mediaeval mind
To the medieval mind, the world was populated not only with living beings but untold myriads of supernatural beings, many of which wanted nothing less than to send a man to perdition for eternity. God and Satan were as real as any man and they were in a constant struggle for the eternal souls of men. Although men claimed that God was at the center of their lives, they believed that God had nothing else to do than to watch every move that every man made and to intervene in the affairs of man so that truth, justice, and right would always prevail.
Even when times were good, times were hard. Life was precarious at the best of times. Flood, drought or pestilence, all attributed to the acts of an angry God, could strike at any time, destroying the harvest or taking one's life. War could break out at any time pushing hapless civilians over the edge into a man-made calamity from which he could not easily recover. In such a time when God was hard to the best of men, why would men think it was wrong to treat the worst of men with harshness?
Peasant and priest alike knew the Bible and from the Bible knew God and knew that God often punished the whole community when one or two of its inhabitants drifted away from God. To succor the heretic, then, was to risk the destruction of the whole community by a vengeful God.
They knew that "God does not keep faith with those who does not keep faith with him" and that it was incumbent upon man not to keep faith with the heretic either2 for the heretic strived to win his soul for the devil as part of the eternal conflict between God and Satan3. Heresy was viewed as treason toward the Almighty Himself.
Laity as well as clergy wanted to send Satan's minions to the stake for such a penalty was fitting for a man who would try to win others' souls for Satan to spend eternity in perdition. As Lea writes, "The cruel ferocity of barbarous zeal which, through so many centuries, wrought misery on mankind in the name of Christ, has been explained in many ways. . . . There is no doubt that the people were as eager as their pastors to send the heretic to the stake. There is no doubt that men of the kindliest tempers, the profoundest intelligence, the noblest aspirations, the purest zeal for righteousness, professing a religion founded on love and charity, were ruthless when heresy was concerned, and were ready to trample it out at the cost of any suffering. Dominic and Francsis, Bonaventura and Thomas Aquinas, Innocent III and St. Louis, were types, in their several ways, of which humanity, in any age, might well feel proud, and yet they were as unsparing of the heretic as Ezzelin da Romano was of his enemies. With such men it was not hope of gain or lust of blood or pride of opinion or wanton exercise of power, but a sense of duty, and they but represented what was universal public opinion from the thirteenth to the seventeenth century 4." Compassion for the heretic was not only a weakness but a sin5; it was the duty of all good and true Christians to identify the heretics in their midst and to punish them without mercy.
End Notes
References
Henry Charles Lea, History of Inquisition of Middle Ages vol 1, (1888) [New York: Harbor Press, 1955 ]