The heart is a container that has the tendency to keep and hold on to unresolved hurts, offences and pains sending equally painful frequent reminders to our emotions, mind and will about what actions to take to protect itself against these unresolved issues.
The best antidote we can put or hide in our hearts to counteract this is the Word of God.
It is a heart regulator and will always give us the God perspective instead of our own humanly twisted perspective.
Thy word have I hid in mine heart, that I might not sin against thee.
Psalms 119:11 KJV