I love John Piper's theology and this is a great article on Five-point Calvinism (as it is called), also known as "Doctrines of Grace" and (my chosen term) "Sovereign Grace."
Incidentally, I do not care for the term "Doctrines of Grace." I do not know about other translations, but in the King James, the English word "doctrines" in the plural is always negative, and always signifies either the doctrines of men, or of demons. I believe this is because there are many "doctrines" just as there are many paths of falsehood, but there is only one truth, which is indivisible in unity, and it belongs to God alone as its author (so I could say, "Doctrine of Grace" but there is more than just Grace to that doctrine, and the phrase is not used as far as I know). It is only when the word "doctrine" is singular that any good comes of it, and not always then in the Scriptures. On the other hand, I think "Sovereign Grace" is redundant (what other kind of grace is there? I mean, even in the secular world by its own definitions I would think grace has to be sovereign in order to be grace). And I do not like the word "Calvinism" for the obvious reasons that I do not believe the "theological system" is man-made (though the term is, I grant that), and the theology would exist whether or not John Calvin had ever been born or come to faith in the first place. But, I will usually call it "Five-Point Calvinism" in public because that term is well-defined, and can be properly understood. In private, I seem to prefer "Sovereign Grace." Whatever the case, I echo the praise of Jonah, "Salvation is of the Lord!" (Jonah 2:9b).
EDIT: Typos. Additional comment.