Season 4, Episode 22: beginning @ 37:25
Brother Alwyn Macomber (a Ranger): ... That is what faith is for. Faith sustains us in the hour when reason tells us that we cannot continue, that the whole of our lives is without meaning.
Brother Michael (potential Ranger): Then why were we born able to reason if reason's useless?
Brother Alwyn Macomber (a Ranger): Not useless, but it's also not enough. Faith and reason are the shoes on your feet. You can travel further with both than you can with just one. If you must have reason for an answer, then consider this. If today the Rangers came back to earth from their place in the heavens, you would not know about it. They would come in secret and move around us and help us and we wouldn't even know that they were here, because the secret that they bring is feared by people who still blame science for the Great Burn.
Brother Michael (potential Ranger): Then you think the Rangers are here today
Brother Alwyn Macomber (a Ranger): Yes, I believe they could be. That's all that faith requires - that we surrender ourselves to the possibility of hope. With that, I am content.