The reason why Christianity spread very fast was because Paul had new message for everyone who wanted a religion which promised life eternal to all believers. His message was simple, all you must do is believe Jesus is the Messiah. That was all. We are saved by faith alone. This gave converts the impression that they didn't have to keep the laws in order to be saved. But then we have some examples of people who didn't keep the law but were saved anyway. Cornelius is one example, the thief on the cross another. There's also Nebuchadnezzar. There are Christians who believe that the laws of Moses are to be followed only by Jews. So if there's a different set of laws which gentiles keep which ones are they? Or do they cherry pick which laws to keep and which ones they don't?