Belief transports us. An idea sown into the consciousness develops there and ultimately takes on the form of something believed. We dwell on it and even live as though it were true, allowing the idea and everything attached to it to enter our lives and carry us to its fulfillment.
Ideas come, take place in our thoughts, and begin to grow. Belief builds and develops until a belief structure settles into place. Ultimately, what began as opinion, suggestion, impression, concept, mental image, or plan grows until little can be done to dissuade us.
Too often we entertain wrong ideas and grow to believe in things the Lord has no part in. Jesus said what develops in the heart eventually comes out—is spoken or acted upon. Since what comes out actually first went in, we are wise to guard what we allow in.