Grudges and resentments are tumors of mortal mind.
“Include moral as well as physical belief in your efforts to destroy error. Cast out all manner of evil. ‘Preach the gospel to every creature.’ Speak the truth to every form of error. Tumors, ulcers, tubercles, inflammation, pain, deformed joints, are waking dream-shadows, dark images of mortal thought, which flee before the light of Truth.” Mary Baker Eddy