"I disapprove of what you say, but I will defend to the death your right to say it."
I don't know about the other quotes, but Voltaire never said this.
As far as the one about the King and the priest, while Voltaire tended to be hostile toward traditional religion, he was a believer in God and also supported a priest on his estate in Switzerland.
I disapprove of what you say, but I will defend to the death your right to say it. 
