“Hurt people hurt people. We are not being judgmental by separating ourselves from such people. But we should do so with compassion. Compassion is defined as a "keen awareness of the suffering of another coupled with a desire to see it relieved." People hurt others as a result of their own inner strife and pain. Avoid the reactive response of believeing they are bad; they already think so and are acting that way. They aren't bad; they are damaged and they deserve compassion. Note that compassion is an internal process, an understanding of the painful and troubled road trod by another. It is not trying to change or fix that person.” -Will Bowen

I thought this was a good one to remember, the shorter version "hurt people hurt people" is helpful for me. Also, was listening to some Wayne Dyer and he quoted Gandhi: "Hate the sin, love the sinner." Bam, love it.

I've been working on responding better to angry people and I think these are useful tools.  Hope this helps you too.