Mystery Quote?

(Day 12) For today, I give you a mystery quote:

Today nobody will stop with faith; they all go further. […] In [the] old days it was different. For then faith was a task of a whole lifetime, not a skill thought to be acquired in either days or weeks. When the old campaigner approached the end, had fought the good fight, and kept his faith, his heart was still young enough not to have forgotten the fear and trembling that disciplined his youth and which, although the grown man mastered it, no man altogether outgrows….

Again, the above is a quote (perhaps even a translation..?). I did not write it, but I greatly admire the one who did.

One more day….