Have you ever been really hot and thirsty and longed for some pure cold water to quench your thirst? Nothing is better on a hot, humid day! If someone added 1% salt to your bottle of water, you would die! The water would become toxic and your body could not assimilate the H20 into your system. A small bit of contaminate can spread through a bottle of water and it is ruined; it becomes impure. The same idea is true in our lives.
What we see and hear becomes part of our subconscious.
Have you ever had a song stick in your mind? That song is called an earworm and it stays in your subconscious and it's hard to shake it out of your thoughts. Earworms are one reason we need to have pure thoughts and faith-based music funneling through our minds. Proverbs 23:7 says, "As a man thinks within himself, so he is." Do you think pure thoughts? If you do, more than likely, your actions will follow.