Just finished RS GCSE (Edexcel), sitting the exams in summer 2017. Not sure if you are doing the new syllabus but, if not, I would recommend 3-4 points per paragraph with strong support using quotes. If they ask you about differences, do one paragraph on one sect/set of beliefs with variation, and then the next of the other. Very short intro (literally two or three lines). This worked for me at GCSE with 100% in my RS gcse so hope it helps you.