While enlisted, I spent some time working the brig (jail, pre-trial and shorter sentences) in a role you'd call a 'transportation officer'. Basically, I moved detainees from one location to another.
An interesting bit of history is that if you lost your prisoner you served their time until the prisoner was back in custody. That rule was long out of effect by the time I served.
Anyhow, and I'm not a religious man and discussing this in a religious context would violate the rules, we had a break room. Between the break room and the secure area was a needlepoint sign that had an interesting saying on it. It said:
"There but by the grace of God go I."
The meaning of which was that we were just one bad decision away from being on the other side of the doors. In a military setting, you don't go to jail to be punished. You're punished by going to jail. The distinction is very important. Detainees are treated with respect and dignity.
It was very strict, but there was respect and dignity. The sign worked as a constant reminder that it could just as easily have been us on the other side of the doors.
It wasn't regulation. It was a very out of place sign. As near as I could tell, it had been there for a long time and nobody knew who hung it there. That one sign, that one saying, has helped me be more compassionate. It has stuck with me for the rest of my life.
So, when you see someone huddled on the street begging for change, think of the sign. When you see someone who snapped and did horrible things, think of the sign.
Dunno where the sign came from. Dunno who put it there. Dunno where the saying comes from. Dunno why a very unregulated sign would be there and allowed to be there. But, I do know the saying has stuck with me for all these years.
(I figured I'd explain, instead of just writing the quote.)