Does mercy have a limit?
Yes and no. Mercy is limitless on God's end, it is on our end that mercy has it limits. In other words, mercy is limited by the narrowness and constriction of our own hearts. God's mercy has no limit but we can limit the expression of God's mercy by saying no to it. God is willing to forgive all of our sins but...
(There's always a but, isn't there?)
... we have to forgive others as well.
When we pray the Our Father we say, "Forgive us our trespasses
AS we forgive those who trespass against us." We see here that forgiving others is one of the conditions for receiving mercy. We have to forgive others if we want to be forgiven ourselves. At the very least, the desire to forgive must be present, Jesus will help with the rest. Desire is a great thing - it leaves a large opening for God to work with.
Not forgiving others means that we want them to be held bound for their sins against us. The wound was too large, too brutal, too cruel to ever be repaired, how can I forgive? This holding bound their sins in turn holds us bound to our own sins while at the same time it binds us in a negative way to the very person we refuse to forgive!
How can that be?! I mean, they did this brutal terrible thing and I could reap what THEY sowed? Huh?
Doesn't seem to make sense, does it?
Until we realize that unforgiveness has the potential to be one of the worst sins of all. It is not a quality from God. Ever. It has one source and the source is evil. According to St. Augustine and St. Thomas Aquinas, evil is defined as "
the absence of good". So, technically evil is not a something, it is an absence of something. In the case of sin (of unforgiveness or any sin) it is the absence of virtue to some degree or another. For instance, satan is evil because there is no good in him. He is virtueless. We, on the other hand, are kind of a mixed bag...lol.
The definition of evil as the absence of good is an important observation because it helps us understand how to overcome both the sins of others against us and the sin we see in ourselves. For the first, we would ask for the grace to forgive, as well as the virtue of love and humility to battle against the lack of love and the pride which leads to unforgiveness. For the second, we would pray for and practice the opposing virtues of whatever vices we are trying to rid ourselves of.
Unforgiveness can lead to a hardening of the heart and if this potential for hardening is fulfilled to its ultimate capacity its end result could be the complete and utter hardening of the human heart, which grace can no longer pierce because the person has refused to allow it to be pierced. It's a total turning away from God, a refusal to love AND a refusal OF love.
In some ways, unforgiveness, if held to the end of life is worse than murder. Why? Because unforgiveness is basically the intent to impose spiritual death. This is the spiritual intent which lies beneath unforgiveness - that a person should reap what they sowed for all eternity. Though we may not see it as such, it is an attempt to usurp the authority of God whose mercy is given to all who ask with sincere hearts. It is an attempt to usurp the justice of God as well. It aligns us with "the accuser of our brethren" instead of aligning us with the Lord, who is rich in mercy.
Unforgiveness is saying to another, "You are not worthy of mercy."
God says otherwise.
"My mercy is greater than your sins and those of the entire world. Who can measure the extent of My goodness? For you I descended from heaven to earth; for you I allowed myself to be nailed to the cross; for you I let My Sacred Heart be pierced with a lance, thus opening wide the source of mercy for you. Come, then, with trust to draw graces from this fountain. I never reject a contrite heart. Your misery has disappeared in the depths of My mercy. Do not argue with me about your wretchedness. You will give me pleasure if you hand over to me all your troubles and griefs. I shall heap upon you the treasures of My grace." (The Diary of St. Maria Faustina Kowalska)
(This post has a second part because it was too long to post all at once. With Lent coming up I thought mercy versus unforgiveness would be a fitting subject to write about. The second part speaks a bit more about the importance of forgiveness and delves into what the Catechism teaches about it.)