“Unforgiveness, resentment, holding grudges is a cancer in our soul. It eats away even at the grace that we may have received. It blocks the work of the Holy Spirit in us. I would go so far as to say it is one of the things that causes the Holy Spirit to flee from us, since, if we are not forgiving, we are not forgiven.”
(Fr Alban Waggener, Holy Trinity Orthodox homily)