Satan doesn’t leave fang marks on the skin but lies in the heart (John 8:44). A lie believed to be true will affect your life as if it were true (Pro4:23). Lies will imprison you but the truth will set you free (John 8:31-32). Who you are can be no better or no worse than the thoughts you entertain in your head.
“Sound doctrine originates with God, is recorded in the Word of God, and is consistent with the whole revelation of God.” -Daren Dirksen: Captivated [series] Colossians-Unity in Doctrine