Why does God have mercy on us?

Why does God have mercy on us? Because he loves us? Because he created us? Because he wants to save us? How about this reason in Paul's letter to Timothy, from I Timothy 1:15-16:

This is a trustworthy saying, and everyone should accept it: "Christ came into the world to save sinners" - and I am the worst of them all. But God had mercy on me so that Christ Jesus could use me as a prime example of his great patience with even the worst sinners. Then others will realize that they, too, can believe in him and receive eternal life."

Interesting thought for today.