For if ye forgive men their trespasses, your Heavenly Father will also forgive you; But if ye forgive not men their trespasses, neither will your Father forgive your trespasses (Matt. 6:14–15).
What a simple and handy means of salvation! Your trespasses are forgiven under the condition that you forgive the trespasses of your neighbour against you. This means that you are in your own hands. Force yourself to pass from agitated feelings toward your brother to truly peaceful feelings—and that is all. Forgiveness day—what a great heavenly day of God this is! If all of us used it as we ought, this day would make Christian societies into heavenly societies, and the earth would merge with heaven. ("Thoughts for Each Day of the Year According to the Daily Church Readings from the Word of God" By St. Theophan the Recluse)
The Sunday of Forgiveness is the last Sunday prior to the commencement of Great Lent. At the onset of Great Lent and a period of intense fasting, this Sunday reminds us of our need for God’s forgiveness and guides our hearts, minds, and spiritual efforts on returning to Him in repentance.