Saint Gregory Palamas on fasting:

"I beseech you, brethren, that during the time of fasting and prayer, we forgive from our hearts if we have truly had or thought we had something against someone, and that we all abide in love. Moreover, let us think better of one another, encouraging each other to love and good deeds. Let us speak well of one another and let us reason and reflect within ourselves on what is good before God and before men, so that we may fast with praise and blamelessness, and so that the prayers we offer during fasting may be pleasing to God, enabling us to properly call Him Father by grace and boldly say to Him: Our Father, forgive us our debts as we also forgive our debtors (Matthew 6:12)."

Taken from the book: "Lord, Enlighten My Darkness," Belgrade, 2005.