"Pain can be used for expiation of our own failings and sins or in reparation for the failings and sins of others.
Expiation. I was a boy about eight or nine years of age, and my brother and I were playing ball in the backyard. I threw a ball accidentally through the neighbor's window. Mother heard it, and she called us in. She sent us to our piggy bank and made us take some money out, go over to the man next door, pay him for the broken window, and also ask him to forgive us.
Now, why not merely ask for forgiveness for breaking the window? Many think that when they do anything wrong, all they have to do is ask to be forgiven. This is only half the story. Every act of injustice disturbs order. That disorder often has to be righted. For example, if I stole a watch, I might regret it and say to the person, 'I am awfully sorry; I stole your watch. Will you forgive me?' He would say, 'All right, I will forgive you,' but he certainly would say, 'Give me back my watch.' Returning the watch would prove the sincerity of my desire for forgiveness.
If we have sins - and who in the name of God has not? - we can ask the Good Lord to take our pains in expiation and atonement. For illegitimate pleasures we make compensation by offering up the sufferings imposed on us, that our ledger on the last day will not find us in the red.
The second way suffering can be used is in reparation. Here we offer it up for others, not just for ourselves. In the physical order, doctors graft skin from a back to a face to restore burned tissue. If a person is suffering from anemia, doctors will transfuse blood from a healthy member of society to the anemic person in order to cure the person of that condition. If it is possible to transfuse blood, is it not possible to transfuse prayer? If it is possible to graft skin, is it not possible also to graft sacrifice and suffering? We live in a world in which we live on the work of others. We do not raise sheep, though we wear woolen clothes. Others do that work for us. So in the great spiritual community of the lovers of God it is possible to offer up pain and suffering in order that others who lack love of God may find it through our efforts. That is reparation.
If it be asked why we should offer our sufferings in expiation or reparation, the answer is because we love. Love does not kill pain, but love can diminish it. A mother sits up all night with her sick child. To the neighbors it is agony; to the mother it is love. There are many real lovers in the world who would willingly take on the pains and the agonies of others if they possibly could. Love in the face of sorrow does not seek isolation. It wants to take on pain as its own. Why should not love in the face of sin and evil want to do the same thing? The great tragedy of our world is that most people who suffer have no one to love.
What is mysterious is not the suffering but how much is missed when we do suffer! Think of all the feverish browws in hospitals who cannot sanctify pain by correlating it to Our Lord with a crown of thorns. Think of the wounded who could sanctify their wounds if they only knew how, by correlating them in some way with Hands that were riven with nails. Think of all the aching hearts with worries, anxieties, and fears who could bear the cross if they only loved a Heart that was opened by a lance.