Pharisees get something of a raw deal in the gospels. In truth, Simon is not really a bad person. He has spent his whole life trying to live up to the laws handed down for generations - really trying to be the best Pharisee possible. Remember that Pharisee wasn't a dirty word... It's simply the name of a group of religious people. Not much different from saying you are Episcopalian, or Baptist, or Catholic. In that day the prominent groups were Pharisees, Sadducees, and Essenes.
But this attempt to be good has left Simon spiritually proud - unable to even imagine his need for God's forgiveness. What Simon doesn't realize, is that God, who is perfect, sees all sin the same. It is only on this earth, where no one is perfect, that we use comparisons to justify our actions, to elevate ourselves or to exclude certain others.
What we need to remember is that God's economy is based on mercy, not merit. To God, we are all his children, all the same; some of us just need more forgiveness than others. And Jesus is there for us - just like he was there for both Simon and for the woman.
How do we respond to Jesus? Do we accept his invitation to lay our burdens at his feet? Do we accept his forgiveness for our sins, both great and small? Or do we take offense that he is generous with others whom we consider to be greater sinners?
Having a heart for God doesn't mean we will always get it right or do it right or be right, but it does mean we really do want to get it right, and when we figure out that we are wrong, we will acknowledge it, repent and try to turn our life around.