Babylon 5, Season 4: No Surrender, No Retreat

[1000 years later, in a future primitive Earth, Brother Alwyn advises the doubting Brother Michael.]

Brother Alwyn:
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:
Then why were we born able to reason, if reason's useless?

Brother Alwyn:
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.

Brother Alwyn:
That is all that faith requires: that we surrender ourselves to the possibility of hope.