Why is Saint Paul important?

Because he wrote most of the New Testament gospels. Because he invented Christianity Acts 11:26 And when he had found him, he brought him unto Antioch. And it came to pass, that a whole year they assembled themselves with the church, and taught much people. And the disciples were called Christians first in Antioch. and Original Sin; Romans 5:12 Wherefore, as by one man sin entered into the world, and death by sin; and so death passed upon all men, for that all have sinned: Jesus was Jewish; Matthew 5:17 Think not that I am come to destroy the law, or the prophets: I am not come to destroy, but to fulfil. Jesus strongly approves of the law and the prophets. 5:18 For verily I say unto you, Till heaven and earth pass, one jot or one tittle shall in no wise pass from the law, till all be fulfilled. "Till heaven and earth pass" Jesus says that the Old Testament laws are binding on everyone forever. 5:19 Whosoever therefore shall break one of these least commandments, and shall teach men so, he shall be called the least in the kingdom of heaven: but whosoever shall do and teach them, the same shall be called great in the kingdom of heaven.