As we get back into our study of Acts, we see a doctrinal conflict arise with on the church. Some men begin to teach that the Gentiles must follow the Jewish Law in order to be saved and accepted into the fellowship. The problem with this is that they were trying to add works to the grace of God in salvation.
People today struggle with this as well. Whether they add rules about appearance, or Bible translation, or worship, or lifestyle, it always takes away from the grace of God in gifting us salvation when we add something that we have to do in order to earn/keep salvation.