Is forgiving an abusive spouse or romantic partner a good idea? 
This is a question many people may ask, particularly since some kinds of false forgiveness often happen during the abusive relationship (it wasn't really that bad, my partner couldn't help it, my partner won't do it again, my partner will change if I do something different, etc). But authentic forgiveness does help people recover once the abusive relationship is over. Emotionally-abused people experience negative outcomes (depression, anxiety, low self-esteem, post-traumatic stress, intrusive memories of the abuse, and difficulty making decisions) long after the emotionally abusive relationship is over. But research by Gayle L Reed (with 20 women who had been out of the emotionally abusive relationship for 2 or more years) has demonstrated that a forgiveness recovery program brings considerable relief from these very problems.

Why does forgiveness help? You choose to give up resentment (which likely is contributing to the depression and anxiety) and you choose to offer goodwill (deciding to act on positive values helps you become the kind of person you would like to be). Then you feel better and you become better. The benefits of forgiving work best when (Reed, 1998) you have social support for forgiveness (other people you know value forgiveness) and with the support of a worldview (Reed, 1998) where forgiveness is valued and there are examples of extraordinary forgiving (such as the forgiveness work of Jesus Christ).

Reed, G. (1998). Forgiveness as a function of moral agency in the context of divorce and infidelity. Master’s thesis, University of Wisconsin-Madison.