Try reading (or listening to) Sinclair Ferguson's The Whole Christ. I'm not a believer at all, so take what I say with a grain of salt, but if the Bible were true, I think Ferguson has given about as clear of a picture as modern humans can have on legalism and antinomianism. Honestly, I think this whole field is an absolute mess, with so much confusion proliferated by both extreme ends that it is hard to even tell where to begin, but I think this book helps bring a balanced understanding back into focus.