Forgiving the Unforgivable

How do you forgive the unforgivable? Someone murders a family member. A drunk driver slams into your car, and you’re in a wheelchair the rest of your life. A trusted friend molests your child. A member of your church who works as an investment counselor persuades you to put your life savings in his hands, and he loses it all. One of your best friends spreads rumors (all untrue) about you that result in your being ostracized by all your other friends. 

You could pick any one of the above, and call it "unforgivable." And sadly most of have personal scenarios that are equally grievous. How could you possibly forgive a person who has done any of these? How can you forgive the unforgivable?