"Do everything without grumbling or arguing (or complaining!), so that you may become blameless and pure, 'children of God without fault in a warped and crooked generation.' Then you will shine among them like stars in the sky."
This one is a really hard one to follow. But we need to do the best we can to do so. Whenever people think that Christians' lives are the easiest, they aren't. They are actually the hardest life to lead. But don't let that discourage you; it is the best life, and so worth it. So let's shine like stars in the sky!