Like all divine qualities, forgiveness is born of a strong, pure will. The purer the will, the less unpleasant experiences affect the mind. The will is normally subservient to the senses and the mind. The mind is impulsive, stubborn, and in a state of flux; yet, it may also be absentminded and apathetic. It broods over the past, worries about the future, and revels in daydreaming and fantasy. Such a mind weakens our will, triggers fear and anxiety in us, and dissipates our precious mental energy.
An undisciplined mind lacks alertness and fortitude. It is unsteady, unreliable, and detrimental to spiritual life. In the Vivekachudamani (325) Sri Shankara describes the fate of such a mind: "If the mind turns away from the ideal and becomes ever so slightly caught in the sensuality of objects, it will continue to go downward, through negligence in recollection, like a ball dropped upon a flight of stairs."
A weak will is strengthened and purified by cultivating alertness. Alertness gathers the mind and lessens its aimless wanderings. We become more conscious and purposeful in our actions. Steadfastness in japa (repetition of a divine name), meditation, and practices of fasts and vigils are further means to strengthen the will.
When the mind of a spiritual seeker comes under the sway of negative thoughts, he should counteract their influence by filling the mind with positive thoughts, as recommended by Patanjali (Yoga-sutras, 2.33). Swami Vivekananda explains: "For instance, when a big wave of anger has come into the mind, how are we to control it? Just by raising an opposing wave. Think of love. Sometimes a mother is very angry with her husband, and while she is in that state, the baby comes in, and she kisses the baby; the old wave dies out and a new wave arises-love for the child. That suppresses the other one. Love is the opposite of anger." Swami Vivekananda then speaks of the power of good thoughts: "The infinite future is before you, and you must always remember that each word, thought, and deed, lays up a store for you, and that as the bad thoughts and bad works are ready to spring upon you like tigers, so also there is the inspiring hope that the good thoughts and good deeds are ready with the power of a hundred thousand angels to defend you always and for ever." Noble thoughts strengthen the mind by elevating it above worldly distractions. A mind filled with pure thoughts never holds on to resentment, but easily forgives.
In our effort to develop the strength and purity to forgive others, prayer to God proves invaluable. A well-known Hindu prayer for spiritual qualities says: "O Lord, Thou art the embodiment of infinite energy; do Thou fill me with energy. Thou art the embodiment of infinite virility; do Thou endow me with virility. Thou art the embodiment of infinite strength; do Thou bestow strength upon me. Thou art the embodiment of infinite power; do Thou grant power unto me. Thou art the embodiment of infinite courage; do Thou inspire me with courage. Thou art the embodiment of infinite fortitude; do Thou steel me with fortitude." (Shukla Yajurveda, 19.9)
Praying for the welfare of all, especially of a person who has caused us pain, is essential to the practice of forgiveness. It heals our mind and cleanses it of vengeful thoughts.