The mark of Cain is stamped ...

The mark of Cain is stamped upon our foreheads. Across the centuries, our brother Abel was lain in blood which we drew, and shed tears we caused by forgetting Thy love. Forgive us, Lord, for the curse we falsely attributed to their name as Jews. Forgive us for crucifying Thee a second time in their flesh. For we knew not what we did.
 Pope John XXIII

Quotes from the same author

Consult not your fears but your hopes and your dreams. Think not about your frustrations, but about your unfulfilled potential. Concern yourself not with what you tried and failed in, but with what it is still possible for you to do.
 Pope John XXIII
Men are like wine - some turn to vinegar, but the best improve with age.
 Pope John XXIII
I am able to follow my own death step by step. Now I move softly towards the end.
 Pope John XXIII
The conviction that all men are equal by reason of their natural dignity has been generally accepted. Hence racial discrimination can no longer be justified.
 Pope John XXIII
Never Hesitate to hold out your hand; never hesitate to accept the outstretched hand of another.
 Pope John XXIII