A rattlesnake, if cornered, will sometimes become so angry it will bite itself.
That is exactly what the harboring of hate and resentment against others is – a biting of oneself. We think we are harming others in holding these spites and hates, but the deeper harm is to ourselves.
“I give them eternal life, and they shall never perish; no one will snatch them out of my hand. My Father, who has given them to me, is greater than all; no one can snatch them out of my Father’s hand. I and the Father are one.””