According to the doctrine of Christianity Jesus, the Son of God abolished the Judaism and founded the Christianity with one stroke. It is the nullification of the Law that is the symbol of his abolition of the Judaism. Jesus showed the worthlessness of the Law as he violated the rule of Sabbath and several ritual laws.
But if we accept this doctrine as true we are faced with an inexplicable question. Peter and the followers of Jesus who participated in the Jerusalem Church observed strictly the Law. Why did the Jerusalem Church observed the Law in disregard of the teaching of Jesus. Marcion who took notice of this fact for the first time offered a strange hypothesis. According to this hypothesis Jesus abolished the Law. But the followers of Jesus backslided to Judaism after the death of Jesus. The modern scholars of theology such as F. C. Baur revived this theory of re-Judaization. The influence of this theory continued until now.
Since the middle of 20th century several efforts were carried out to overcome this theory. The active and sincere study of Judaism changed the prejudiced view that Jews in the time of Jesus pursued the strict and formal legalism. For example E. P. Sanders showed that the 1st century Palestinian Jews did not believe in works righteousness. Especially the Pharisees, the opponents of Jesus tried to reinterpret the Law considering the living conditions of common people and to alleviate the burdens of the common people.
We should interpret the acts and teachings of Jesus described in the New Testament in this new point of view. The contemporaries of Jesus did not think the acts of Jesus such as touching a leper as disregard for the Law. Because the Pharisees did not regard everything in the Torah as equally significant. Contrary to the common view they didn’t stick to legalism but were interested in searching for fundamental truths in the Torah. So the leaders of Pharisees, such as Hillel and Akiva, regarded love for God and neighbors as the greatest principle of the Law. Jesus gave emphasis to the spirit of the law like these leaders. Therefore he didn’t try to abolish but to perform the Law.
The followers of Jesus knew the teachings of Jesus. Their observances of the Law in the early time of Jerusalem did not run counter to the teaching of Jesus. On the contrary because they did remember the teaching of Jesus on the Law, they could agree the opinion of St. Paul who argued the abolition of Law for the Gentiles.