Belief in oneself is incredibly infectious. It generates momentum, the collective force of which far outweighs any kernel of self-doubt that may creep in.
There is no doubt that the actions of ISIS are designed to amplify their power and the threat that they pose. That helps them recruit. That adds in the twisted thoughts of some young person that they might want to have carry out an action that somehow they're part of a larger movement.
I believe that the starting point of faith is some doubt, not bein' so full of yourself and so confident that you are right and that God speaks only to us and doesn't speak to others, that God only cares about us and doesn't care about others.
Should doubt knock at your doorway, just say to those skeptical, disturbing, rebellious thoughts: "I propose to stay with my faith, with the faith of my people."
Doubt, indulged and cherished, is in danger of becoming denial; but if honest, and bent on thorough investigation, it may soon lead to full establishment of the truth.
There is nothing makes a man suspect much, more than to know little, and therefore men should remedy suspicion by procuring to know more, and not keep their suspicions in smother.