What I think Nietzche thought about this was that one must aspire to "superhuman" thoughts and actions to move in that apparent void and draw sustenance from it; what we are now is not enough at all, and, like in a desperate last stand, heroism one never knew one had is the only way to survive.
And, terrifyingly enough, we might at some need to sacrifice or deny some part of ourselves to reach across that abyss. (Curiously, this does not feel incompartible with my faith)