Christianity according to Matthew is very similar to Judaism. Though the attribution to Matthew rests on tradition—the Gospel doesn’t mention his authorship—the Gospel evidently originated in the Jewish sect whose members were historically close to Jesus. The Gospel of John contains so many Hellenic concepts that its association with Jesus, a Jewish teacher, is doubtful. Gospels introduce different doctrines, and it is reasonable to take Matthew for the benchmark of Jesus’ teaching.

Jesus demanded observance of the Jewish law. Until heaven and earth end, not a single stroke or dot from the letter will pass away. If you want to be good, observe the commandments. Do as they [the Pharisees] tell you, but not as they do, because they don’t practice what they are saying. When accused of a moderate Sabbath violation by his pupils, Jesus insisted that the violation was an exception. He defended his right to heal on the Sabbath rather than ignoring the holy day. Jesus paid the Temple tax and asserted that the Temple altar is sacred (more than the offerings). He appealed to God in his last cry. Nowhere in Matthew does Jesus proclaim himself a divine hypostasis. Speaking to Jews, he calls God the father of all, implying that they are sons of God in the same sense that he is. Jesus extensively quotes the Bible. A popular teacher, he protested the “Talmudization” of Judaism, and accused the Pharisaic rabbis of overturning the sense of the law by twisting its letter (passing the assets due to one’s parents to the Temple. That Pharisaic trick, although formally compliant with the law, violated the commandment to respect the parents). Talmudic sages similarly condemned legalistic excesses: among the seven kinds of Pharisees, the worst show how to circumvent the law while formally adhering to it.

Paul rejected the law and introduced numerous arbitrary ethical regulations instead. The victorious Church re-introduced the commandments. Reasonably detailed religious legislation is necessary, just as with secular laws. Most Christians insist on observing the Ten Commandments, though they ignore the prohibition of divine images (statues and paintings) and the requirement of Sabbath. Nothing in the Gospels supports abrogation of those two commandments while accepting the rest. Either all the Ten Commandments are divine and valid, or Jesus’ resurrection abrogated them all. Christianity follows many ethical commandments besides the Ten, notably the prohibitions of incest and homosexuality. There is no theological justification whatsoever for picking and choosing among the commandments. Kosher laws were abrogated with Peter’s revelation that everything that God has made clean, is clean. That reasoning would allow cannibalism, since God created humans, too. James specifically prohibited Christians to eat meat with blood; that requirement is ignored today.

Many Christians consider Judaic law over-developed. Many Jews think so, too. Many Americans consider their tax law cumbersome, but accept the concept of taxation. God undoubtedly does not care whether we switch on the lights on Saturday; similarly, he is probably indifferent to us murdering each other. The rules were given for us, not for God. Jesus questioned the details of the Pharisaic teaching, not the commandments.

Jesus fits the mold of Jewish tradition. The prophet Elisha also multiplied bread and resurrected; the miracle of healing was common.

Christians believe that Jesus brought salvation, and that they can share in it through faith. What is faith? It is commonly defined as belief in the fact of Jesus’ resurrection. For those who believe, what are the practical implications? Could they go on sinning? The Church has long recognized that gap in the Pauline doctrine. Prevalence of faith became interpreted thus: human actions, however good, are too insignificant to earn the eternal salvation, and granting it is an act of benevolence presupposed by faith. Good deeds, however, are still necessary. It is a sin to repent without a firm resolve to mend one’s ways. What ways are good? What is sinful? Jesus answered those questions: if you want to be good, observe the commandments. Sin could only be defined as a violation of the laws. Jesus promulgated no other laws besides the commandments, thus, violation of the commandments constitutes sin in Christianity, just like in Judaism.

A popular view is that Jesus’ instruction to love one’s neighbor renders literal adherence to other commandments unnecessary. There is no support in the Gospels for that view whatsoever, and in fact, Jesus explicitly called for observance of the commandments. Besides, “Love thy neighbor” was commanded in Leviticus centuries before Jesus, but the commandments were not abrogated. “Love” could be interpreted very flexibly: love of Jesus caused pogroms and crusades. No state exists with only a constitution; France has many laws besides the basic, Liberté, Égalité, Fraternité. Founding principles need to be developed into law.

Jewish and Christian law, as can be judged from the Gospel of Matthew, is similar.