Here is a quote from Obama's speech at the eulogy in Arizona.
"I believe we can be better. Those who died here, those who saved lives here – they help me believe. We may not be able to stop all evil in the world, but I know that how we treat one another is entirely up to us. I believe that for all our imperfections, we are full of decency and goodness, and that the forces that divide us are not as strong as those that unite us."