The Lord is my rock, and my fortress, and my deliverer.
My rock - my support underneath;
My fortress - my defense around;
My deliverer - my protector from within.
If you’re a Christian you too have this impenetrable and unbeatable Protector. If you are not a Christian, you have no protection at all. You are totally at Satan’s mercy. I think I would feel really nervous if I were not a Christian.