[Bible] Does Jesus Reset Biblical Morality?

This is neither pro- or anti- Christian, as seems to be the thread trend nowadays. I just want to know, is there anywhere in the New Testament where Jesus is reported to have said that we can disregard the rules/teachings of the Old Testament? Does he comment on the old texts at all?

Put differently, are there any good Biblical reasons to ignore some of the messy rules, laws, and apparently condoned behaviours that occur in the first few chapters of the Bible?

Yes and no. Jesus’s teachings on the Law and “righteousness” are a bit opaque, sometimes appearing to endorse it and sometimes to supersede it.

The explanation, so far as Christians are able to provide a rationale here, lies in two divergent strains of Judaistic practice: the tendency to legalism, exemplified by “the Pharisees” [specifically one group among them whom he disliked], on the one hand – God’s word is law, to be obeyed to the letter and to be enforced on the community; and on the other, a tendency to look at the spirit of the Law, what it was seeking to instill in the people. The prophets, many of the great rabbis, etc., took this perspective; Hillel is famous for it.

Jesus clearly adhered to the “meaning of the Law” understanding of God’s will, and this is exemplified in what he called most important: “Thou shalt love the Lord thy God, with all thy heart, and with all thy soul, and with all thy mind, and with all thy strength. This is the first and great commandment. And the second is like unto it: Thou shalt love thy neighbor as thyself.” Both these, by the way, are quotations from Torah. And “Do unto another as thou wouldst have him do unto you.”

Evidently, to Jesus, the Law is to be kept, but to be kept creatively, in a manner that focuses on God’s intent in giving it: devotion to him and fair, compassionate treatment of one’s fellow man. And the examples where he appears to supervene it are ones where a literalistic reading of a passage would result in action contrary to the two great commandments.

This is slightly post-Jesus, but one of the major controversies of the earliy Church was over the question of whether Gentile (non-Jewish) converts to Christianity should be required to conform to the Jewish Law (with its dietary requirements, circumcision, etc.).

The issue is described in the 15th chapter of the book of Acts, and there are also references to it in Paul’s letters.

Mark 2:23-28: We shouldn’t be slaves to the Law (specifically in this case, the Sabbath)

Acts 10:9-16: All animals are made clean

On the other hand, we have Matthew 5:17-20: