You never know how much you really believe anything until its truth of falsehood becomes a matter of life and death to you. It is easy to say you believe a rope to be strong and sound as long as you are merely using it to cord a box. But suppose you had to hang by that rope over a precipice. Wouldn't you then first discover how much you really trusted it?
Only He who really lived a human life (and I presume that only one did) can fully taste the horror of death.