What's a nice Jewish boy ... ?
But back to his teachings, there was nothing there that wasn't based on the revealed wisdom of God, the Torah.
Also called the Pentateuch or the Five books of Moses, the Torah, despite misconceptions by some Christian teachers, means 'teaching', a positive attribute, rather than 'law', with its more negative, restricting connotations.
Jesus speaks of the Torah. He said that he hadn't come to abolish the Torah, rather to fulfil it. This is a bold, but very important, statement. Because, to Orthodox Jews, Torah is of the utmost relevance, one of the 'three pillars' of Judaism, along with God and the people of Israel.
So what did Jesus mean?
What he meant was that he had come to make clear the full and proper sense of the Torah. The clue to this is actually given in the Hebrew Scriptures, in the Book of Jeremiah, Chapter 31. Here we find the clearest indication that God was going to deal with his people in a fresh new way. This is what it says.
"The time is coming," declares the LORD, "when I will make a new covenant with the house of Israel and with the house of Judah. It will not be like the covenant I made with their forefathers when I took them by the hand to lead them out of Egypt, because they broke my covenant, though I was a husband to them," declares the LORD. "This is the covenant I will make with the house of Israel after that time," declares the LORD. "I will put my law (Torah) in their minds and write it on their hearts. I will be their God, and they will be my people. No longer will a man teach his neighbor, or a man his brother, saying, 'Know the LORD,' because they will all know me, from the least of them to the greatest," declares the LORD. "For I will forgive their wickedness and will remember their sins no more."
So Jesus didn't teach the Jews to turn their back on their past. Instead, through his teachings, the Torah was to come alive, even 'written on their hearts'.
He was speaking against the established Judaism of the day, which had simply become an outward show of religiosity. What he was saying was that it wasn't important how smart you looked in the synagogue, or the length, quality and volume of your public prayers, it was the quality of your heart that was important.
He developed these ideas through many sermons given in various places. For example, when considering adultery, he taught that anyone who even looks at a woman lustfully has already committed adultery with her in his heart. Just think how many marriages could be saved if people honestly followed this teaching, with lust being checked at an early stage before thought turned to action!