The truth about Christianity is that it is a severe and practicable religion, not a beautifully ideal but impracticable one. Its moral precepts (except for the stricter laws about marriage that Christ enacted, abrogating some of the permissions of the Old Law) are those of the Old Testament; and its God is the God of Israel.
It is ignorance of the New Testament that hides this from people. It is characteristic of pacifism to denigrate the Old Testament and exalt the New: something quite contrary to the teaching of the New Testament itself, which always looks back to and leans upon the Old. How typical it is that the words of Christ “You have heard it said, an eye for an eye and a tooth for a tooth, but I say to you . . .” are taken as a repudiation of the ethic of the Old Testament! People seldom look up the occurrence of this phrase in the juridical code of the Old Testament, where it belongs, and is the admirable principle of law for the punishment of certain crimes, such as procuring the wrongful punishment of another by perjury. People often enough now cite the phrase to justify private revenge; no doubt this was as often “heard said” when Christ spoke of it. But no justification for this exists in the personal ethic taught by the Old Testament. On the contrary. What do we find? “Seek no revenge,” (Leviticus xix, 18), and “If you find your enemy’s ox or ass going astray, take it back to him; if you see the ass of someone who hates you lying under his burden, and would forbear to help him: you must help him” (Exodus xxiii, 4-5). And “If your enemy is hungry, give him food, if thirsty, give him drink” (Proverbs xxv, 21).
This is only one example; given space, it would be easy to shew how false is the conception of Christ’s teaching as correcting the religion of the ancient Israelites, and substituting a higher and more “spiritual” religion for theirs.
(G. E. M. Anscombe, “War and Murder,” chap. 3 in Absolutism and Its Consequentialist Critics, ed. Joram Graf Haber [Lanham, MD: Rowman & Littlefield Publishers, 1994], 29-40, at 35 [italics in original] [essay first published in 1961])