Would you be frightened if someone came up to you and said, “Hey, there’s a Greek god/goddess living inside of you”?
The twelve people who were told this were not frightened. They were freaked out. They were all in their early teens. After all, how would you react if you were told that? You sure as heck wouldn't be serene.
Everyone eventually works up the courage to do what they're suppose to, but they are still scared out of their minds. No one's prepared for the outcome of their first mission. Who would be?
As they say, with great power comes great responsibility.