Worth visiting for the view alone. If you're so inclined, attend service. Be sure to leave a donation, and light a candle.
Even though I'm not terribly religious - I jive spiritual - there's something about the art that sends chills up my spine. This place is designed to make one feel small, and very, very mortal, and it does a good job of it.
Visit the gardens, toss a coin into the pool, and meditate on that mortality.