The Usefulness of Pain

Someone who knew what he was talking about once remarked that pain was the touchstone of all spiritual progress. ~ AA World Services Inc. Twelve Steps and Twelve Traditions (pp. 93-94). AA World Services, Inc. Kindle Edition.

Is it true pain is the touchstone of all spiritual progress?
Touchstone: a piece of fine-grained dark schist
or jasper formerly used for testing alloys of gold
by observing the color of the mark that they made on it.
OR a standard or criterion by which
something is judged or recognized.
The he character of Touchstone
in Shakespeare's As You Like It,
is described as "a wise fool
who acts as a kind of guide
or point of reference throughout the play,
putting everyone, including himself,
to the comic test.
So, is PAIN a touchstone of spiritual progress?
If a touchstone is "a fundamental
or quintessential part or feature"
yes, almost all growth or progress
comes by way of pain.
Pain is clearly involved in true growth or progress.