Today is the Feast of St Faustina

So pray a Divine Mercy chaplet and contemplate what mercy is.

More amazing than justice, mercy.

Undeserving and unworthy, we often spend a good deal of time demanding that we receive justice, restistution and our rights. 
And we often consider mercy one of those rights. But it is not, mercy is gift. Bestowed upon one by someone greater.
We need mercy. We wither away without it. And we need to bestow mercy on others - we forgive our children a million times for things. That is mercy. Occasionally we are called to forgive those who really deeply hurt or betray us. There's no real earthly reason to do so, but for the sake of our own souls and our minds, we ought to.
In the Riches of Mercy, Pope John Paul II wrote:

"The present-day mentality, more perhaps than that of people in the past, seems opposed to a God of mercy, and in fact tends to exclude from life and to remove from the human heart the very idea of mercy. The word and the concept of "mercy" seem to cause uneasiness in man, who, thanks to the enormous development of science and technology, never before known in history, has become the master of the earth and has subdued and dominated it."

The whole thing is worth the time to read it.

St Faustina's diary is available at this site.  There is much encouragement and hope within its covers. Bear in mind that Jesus died for us to want His love.