From the article:
Many researchers think forgiveness - a virtue embraced by almost every religious tradition as a balm for the soul - may be medicine for the body. They have shown that "forgiveness interventions" - often just a couple of short sessions in which the wounded are guided towards positive feelings for an offender - can improve cardiovascular function, diminish chronic pain, relieve depression and boost quality of life among the very ill.
Mind you, the article can only argue the benefits from a secular perspective, without giving anything other than personal benefit as the reason for taking the step of forgiving, and what's more, locating the power to forgive in the will of the one forgiving. That's a shaky reed indeed!
Christians struggle to forgive others too. But they know that the source of all power to forgive comes from God, and is based on the overwhelming and infinite grace that God has shown to us in Jesus Christ. The source of our ability to forgive others is our thankfulness and knowledge of what God has done for us.
Col. 3:12 Put on then, as God’s chosen ones, holy and beloved, compassion, kindness, humility, meekness, and patience, 13 bearing with one another and, if one has a complaint against another, forgiving each other; as the Lord has forgiven you, so you also must forgive.
This is not easy! But without knowledge of God's forgiveness, it is close to impossible, and may even be impossible.