Because of our Undeserving
Have you ever loved someone so much that you wished you could take that person's place in suffering? If you child is sick, have you thought, "I would be sick so that he could be well."?
As Christians, we believe that Christ took on our pain and suffering and sin so that we could be whole. He suffered and died, and then was victorious over death - in a way we could never have been without him. That being said, I've never thought of it like this:
The New Covenant means that "God's love becomes a suffering love: a love that suffers because it is not reciprocated, a love that suffers because we who are loved suffer and suffer precisely in our failure to reciprocate By giving us the cup to drink, Jesus is saying that in loving us God "bleeds" for us - not "even though" we don't give a damn, but precisely because we don't. God keeps his part of the covenant whether we keep our part or not; it's just that one way costs him more." Frederick Buechner, Wishful Thinking
If God were fair, then when we disobeyed, God would stop loving us - our disobedience would break the contract with God. But God loves us so much that he suffers in our disobedience, becuase God knows our disobedience brings us pain. We understand that - when our children disobey and are hurt because of it, we suffer with them.
It's grace - not love in spite of our undeserving, but love because of our undeserving.