There are a series of teachings from the Old Testament that the Lord Jesus refutes. Were all these teachings from God or tradition of men? some were given to Moses by God, but the Lord Jesus seems to disagree & refute them. We can read a series in Matthew 5:21-39. What is the explanation of this? Did the Lord Jesus come to change the Law of Moses?
Jesus neither said nor did anything that was contrary to the Law of Moses. He was after all, the Author of that Law. In Matt. 5:17 He said that He didn’t come to abolish the Law but to fulfill it.
He did criticize the religious leaders for adding to it, and for keeping the letter but not the spirit of the Law. Matt. 5:21-39 is a case in point. For example, He said in effect that just because we don’t murder anyone, doesn’t mean that we’ve kept the commandment. The seeds of murder are sown in the anger in our hearts and make us just as guilty as if we’d committed the crime. He was teaching us that thinking about breaking the Law is as bad as if we do it.
God’s Law is still God’s Law. And violations of His law are still called sins. The difference for the Church is that He paid the penalty in full for all our violations in advance, so we don’t have to.