In this one sentence, usually at the beginning of his writings, he will tell you the purpose for the entire book or sermon. Keep this purpose in mind because everything he writes after this purpose is designed to prove that what he is saying is right. Get the main point of each paragraph and section after the purpose has been declared. Getting these main points down will help you follow the flow of Edwards' argument. As you outline point by point, you will see exactly what Edwards is saying.
Many people think outlining is bad, no fun, a waste of time.
Follow Edwards' outline. He outlines his works for you. Pay close attention to these outlines. Again, as you see the outline, you will see the purpose for the writing become clear. Concentrate on the sermons.