You who are trying to be justified by law have been alienated from Christ; you have fallen away from grace.
To some, the term fallen from grace means the loss of their salvation. Regardless whether this is possible according to other passages in scripture, it is not what Paul is writing about in Galatians.
Instead, what Paul is writing about is literally giving up the grace that God has given them. Instead of relying on God’s grace for their salvation, they believe that their works are saving them. Or on the flip side of this, they believe that if they sin too often or too greatly, that God will remove His grace from them – as if they had any right to it in the first place since they were sinful from the start.
We cannot earn God’s grace. We can’t be righteous on our own. The Pharisees believed they were righteous and stated that they followed all of God’s laws but this simply wasn’t the case. The Pharisees made up extra laws in order to keep from accidentally disobeying one of God’s laws.
But the Pharisees obeyed the letter of the law – their own law in many cases – but ignored the spirit of God’s laws. As Christians we too can sometimes become overzealous in our attempts to not sin.
Without a doubt, there are movies we shouldn’t watch, dances that shouldn’t be danced, and thousands of websites that shouldn’t be viewed. But this doesn’t mean movies, dancing, or the internet is bad in itself. We must follow the spirit of God’s law and realize that we are saved by God’s grace alone. Obedience to the law doesn’t make us righteous because we can’t obey 100%.