Remember what Jesus said before about a tree and it's fruits? He mentions this again as He is talking to the Pharisees and scribes. He said, Either make the tree good, and his fruit good; or else make the tree bad and his fruit bad, because a tree is known by his fruit. O generation of vipers, how can you, being evil, speak good things? Because the words you speak come from your heart. A good man, out of the goodness of his heart, brings about good things. A bad man out of the wickedness of his heart, brings about evil. But I say to you, That every vain word that men speak, they'll give account of in the day of judgment. By your words, you'll be justified and by your words you'll be condemned.

What do you think that means? What it boils down to is this: Evil can't be hidden forever. It's gonna come out sooner or later and even if you try to hide it from the world, God knows if it is inside you. Jesus wasn't only talking about things that are spoken either. Don't forget, He's the one who said, If you thought it, it's the same as doing it. IF you did it with your heart. This is pretty scary at first, but stay with me here. Of course thoughts are gonna come into your head that you don't want or mean to think. It's the devil's mission to put them there. IF YOU ENTERTAIN those thoughts, if you ponder on them, if you don't evict them right away, if you don't catch them and exterminate them with TRUTH or prayer or good thoughts, THAT is when bad fruit begins to grow.