What is in your heart is the spirit of man. The mind, will and emotions is the soul of a man. The way I see it is, my child came into this world not knowing anything. He looks to his parents for food, shelter, provision, and guidance. He has no idea the perils that the world has for him without those things in place and does quickly learn to stay close to home to be safe. Even animals know to do this; however, we know animals have died in the hierarchy of the jungle - oddly enough this is also true with human life.
nevertheless, humans think one way as a child and completely different as adults. That which I believed as a teen is completely different int he way I think now. Therefore, my mind, will and emotions will change. My heart is steadfast in the principles of Christianity. Trusting in the only God that created all. Seeing that He knows all and sees all, it would be to my best interest in trusting in Him. I can only do that with my heart.