Why is Iran trying to kill a Saudi Muslim?

“The forces working against us are very powerful and well entrenched. And one of the greatest dangers is that on their side they are firm and convinced and resolute. Whereas on our side we are weak and undecided and irresolute. And in such a combat, it is not difficult to see which side would prevail. I think the effort is difficult and the outcome is uncertain, but I think the effort must be made. Either we bring them freedom, or they destroy us.”