How and why did the early style of Michelangelo, as seen in David, change to his later style, as seen in the Last Judgment?

What will be an ideal response?

Essay responses should include these points:
His work became increasingly religious.
He began to subvert the Renaissance ideals of human perfectibility and denied his own youthful idealism.
In the Last Judgment, he painted a writhing swarm of resurrected humanity, with the saved dragged from their graves and pushed up into a vortex of figures around Christ.
David embodies the antique ideal of the athletic male nude, but the emotional power of the facial expression and concentrated gaze is new.