Just as the body needs to keep in shape so does the Spirit. Bottom line is you cannot keep your spirit in shape and in check without exercising your spirit by Faith. Church is like a gym. The Holy Ghost is your personal trainer. Reading and applying commandments is like your work out and eating healthy is like learning true doctrines. Just as we have a body that needs our care and respect so do we have a spirit that can get weak and have problems without proper care and respect. Work it out!