How can appearances be deceiving?

1 Samuel 16:6-7When they arrived, Samuel took one look at Eliab and thought, “Surely this is the Lord’s anointed!” But the Lord said to Samuel, “Don’t judge by his appearance or height, for I have rejected him. The Lord doesn’t see things the way you see them. People judge by outward appearance, but the Lord looks at the heart.”

Matthew 23:28“Outwardly you look like righteous people, but inwardly your hearts are filled with hypocrisy and lawlessness.”

The appearance of a person’s body does not reveal the condition of that person’s heart.