"But the Lord said to Samuel, 'Do not consider his appearance or his height, for I have rejected him. The Lord does not look at the things people look at. People look at the outward appearance, but the Lord looks at the heart.'” – 1 Samuel 16:7 (NIV)
The downside to not having read all of the Bible is that I still don't know the full context in which some of these things are being spoken so it took me a second to fully grasp what God was referring to. Initially I thought Samuel was judging someone by there "unattractive" appearance and dismissed them and God was telling him not to. Then I realized God had rejected the person being judged physically -which means Samuel was actually looking favorably on the person (who was probably a handsome, popular king or something) and God was telling him not to trust or admire that person because inside the man was condemned.
Kind of suggesting that the devil often appears beautiful and trusting to lead people into false favor with him. Like the serial killer Ted Bundy.