Everyone

Everyone in the world must play his part in its redemption, in order to recognize that the world has been redeemed. 

You cannot see the invisible.

Yet if you see its effects you know it must be there.

By perceiving what it does, you recognize its being.

And by what it does, you learn what it is.

You cannot see your strengths, but you gain confidence in their existence as they enable you to act.

And the results of your actions you can see.