But that's the Old Testament

"But that's the Old Testament" is an argument used by Christians when they wish to ignore or glaze over specific Old Testament laws and stories. (This is a form of cherry picking). It is often used when counter-apologetics bring up:


 * The numerous massacres performed by or under the direction of God as written in the old testament.
 * Laws regarding the keeping and treatment of slaves.
 * The requirement of animal sacrifice.
 * The punishment of stoning to death.
 * As well as any individual laws they do not wish to follow e.g.: dietary laws or the prohibition of wearing blended fabrics.

Apologetics
Most Christians will claim that when Jesus died, it nullified the Old Testament laws.

Counter-apologetics
This argument is flawed in several respects:

1. They continue to quote the Old Testament laws that they do wish to follow.

2. According to the New Testament Jesus is quoted as saying "Whosoever therefore shall break one of these least commandments, and shall teach men so, he shall be called the least in the kingdom of heaven: but whosoever shall do and teach them, the same shall be called great in the kingdom of heaven."

3. Jesus quoted an Old Testament law in light that it is still of God that Christians wouldn't normally follow, "And he said to them, “You have a fine way of rejecting the commandment of God in order to establish your tradition! For Moses said, ‘Honor your father and your mother’; and, ‘Whoever reviles father or mother must surely die,’" (Mark 7:9-10).

4. In every major mainstream branch of Christianity, Jesus is considered identical to God. That they should be treated as two separate deities is a creed of the largely-extinct Christian branch of Gnosticism. If a Christian wishes to contrast the "jealous Old God" with the "merciful New God", he is committing the Gnostic heresy by semantics, and should be very glad he does not live in a time and place where this could be punished with torture and/or death.

An illustration of this Trinitarian point is made at this similarly-titled page on "BibleTrash.com"
 * We are told explicitly that Jesus Christ IS THE GOD OF THE OLD TESTAMENT! You probably already accept this. But, by logical extension, you must also accept therefore that it was Jesus Christ who ordered the Israelites to slaughter millions of defenseless men, women and children in the conquest of Canaan; it was Jesus Christ who killed every firstborn child in Egypt; it was Jesus Christ who ordered king Saul to butcher thousands of children and babies in the genocide of the Amalakites; it was Jesus Christ who ordered the Israelites to capture and mass-rape 32,000 young girls of the Midianite tribe after killing their families;  it was Jesus Christ who struck dead 50,000 innocent people at Beshemish for merely looking into the ark of the covenant; it was Jesus Christ who caused the painful asphyxiation of every man, woman, child and animal on the face of the earth during the flood of Noah (with the exception of 8); and it was Jesus Christ who condemned every person ever born to a state of eternal suffering, all because 6000 years ago a curious and naive woman ate a piece of fruit.

5. The New Testament, despite being much smaller and covering a much shorter period of time in its story, nonetheless manages room for some "Old Jealous God"-style condemnations. Gospel of Matthew, 10:11-15:
 * Whatever town or village you enter, search for some worthy person there and stay at his house until you leave. As you enter the home, give it your greeting. If the home is deserving, let your peace rest on it; if it is not, let your peace return to you. If anyone will not welcome you or listen to your words, shake the dust off your feet when you leave that home or town. I tell you the truth, it will be more bearable for Sodom and Gomorrah on the day of judgment than for that town.

Are the people of said town merely to feel so ashamed that their experience is worse than burning alive? Or is this a literal threat against entire communities of people? Plenty of modern Christians — though not the true kind, of course — are perfectly okay with the latter interpretation, and, following from both Scripture and the doctrine of omnipotence, see the hand of God in plenty of natural disasters, as just punishment for said towns having at least one unbeliever.

6. Regarding Hell, Christopher Hitchens makes the following point:
 * The god of Moses would brusquely call for other tribes, including his favorite one, to suffer massacre and plague and even extirpation, but when the grave closed over his victims he was essentially finished with them unless he remembered to curse their succeeding progeny. Not until the advent of the Prince of Peace do we hear of the ghastly idea of further punishing and torturing the dead.

Jesus only has to mention the doctrine of Me-or-Hell once to automatically condemn billions more than the Old Testament ever does. And Jesus references Hell a lot.

7. Finally, decapitate their argument by quoting Jesus with "Do not think that I have come to abolish the law or the prophets.  I have come not to abolish but to fulfill.  Amen, I say to you, until heaven and earth pass away, not the smallest part or the smallest part of a letter will pass from the law, until all things have taken place." (Matthew 5:17)
 * Christian answers to this point may take one of the following forms:
 * "smallest part or the smallest part of a letter" (also translated "jot or tittle"), is metaphoric hyperbole. Given that it is discussing the literal word-for-word structure of Old Testament texts, this makes one wonder how in the world poor Jesus can ever make his words taken seriously. Even when he says "Be a literalist about the Law", he's taken non-literally.
 * "All things", in fact, "have taken place". The world has, metaphorically, already ended with the crucifixion of Jesus, and we are in a new age. This view is called Preterism. It is not the mainstream view regarding Jesus's (and/or other Biblical speakers') discussion of the End Times.
 * It doesn't matter, because portions of the New Testament do explicitly overrule old laws, most especially kashrut dietary laws and certain rigid interpretations of keeping the Sabbath holy. Arguing that one's holy book contradicts itself, of course, doesn't exactly help one's case much. And despite those parts, nothing in the New Testament explicitly nullifies the old laws as a whole; there is nothing to suggest, for example, that the forbidding of wearing mixed clothing is no longer in effect. (Or that God is sorry for butchering all those people.)