Praise be to our Creator, there is no contradiction in Islam between reason and faith. In fact, Allah informed us that failure to use one's reason correctly is a cause of entering hell-fire: "And for those who disbelieved in their Lord is the punishment of Hell, and wretched is the destination.....And they will say, "If only we had been listening or reasoning, we would not be among the companions of the Blaze."" [67:6,10]
The Shaykh told us that Imam Ahmad said that Iblees was the first creature to use fallacious reasoning when he refused to prostrate to Adam, claiming that he was better than Adam because he was created from fire. Of course, there are several unproven assumptions in Iblees's reasoning, among them: what makes fire better than earth?
And so our lesson is that each and every one of us should scrutinize our reasoning. Do we have revelation to back up our beliefs and practices? Is our interpretation of those sources sound? Nor should we shy away from having our reasoning challenged. Challenging each other's reasoning doesn't need to involve condemnation, and we all need to be honest with ourselves and each other in the process.