Faith.
>Trust/Belief in somebody/something< [U] a strong belief that someone or something can be trusted to be right or to do the right thing:
have faith in I have great faith in her, she won't let me down.
destroy/restore somebody's faith in (=take away or give back their faith) It's really restored my faith in the human nature.
lose faith in: The public has quite simply lost faith in the government.
What happens when someone challanges your faith and you have no way to back it?
Defend your faith.
Defend it well...