Jesus says the second greatest commandment is to love our neighbor as ourselves. But that implies we love ourselves first. We find our self worth in God. God created us on purpose. God loves us so much that He sent His son to die so that we might live. We are worthy of love, not because of what we do, but because God thinks we are worthy of love.
But that same logic says that other people are worthy of love as well. They are created by God on purpose. They are loved by God and saved by God. Therefore, we love our neighbors for the same reason that we love ourselves, because God thinks they are worthy of love.
Audio: Love Thy Neighbor as Thyself Readings (Pentecost XIV, Proper 25)