A fellow by the name of Bruce Fisk received what four imams considered top flight Islamic "evangelization". If you read his account, pay close attention to your feelings as you are winged so high above the ground by their arguments that you feel it isn't safe to jump.
Should he have argued with them from his Evangelical point of view?
How would one talk with them about the need for a Savior? Grace? Forgiveness? A Divinity who is perfect love and does not welcome the bloodshed of unbelievers? [h/t: New Advent]