"Because" is ambiguous. It could mean only a subjective motive ("Because I'm paranoid, I believe that man is going to kill me"), or it could mean an objective reason ("Because he's pointing a gun at me and squeezing the trigger, I believe that man is going to kill me"). "We believe in angels because we seek security" is only a subjective, psychological motive. "We believe in angels because God has revealed to us in the Bible that they exist" is an objective reason"