In a letter responding to a religious sister undergoing sufferings as to console her, in 1721, Paul of the Cross wrote the following:
O sweet troubles, treasured tokens of the Sacred Heart of our spouse, Jesus Christ! Whoever loves Jesus seeks nothing else but suffering. I am consoled to know that you are one of those very happy souls who walk the path to Calvary following our Redeemer. Happy are you if you follow this precious path, for one day in the company of other lovers of the cross you will sing, ‘Your crosses, dear God, are the joys of my heart.’
May this be said of us, as well. And may this be our song: “Your crosses, dear God, are the joys of my heart!”
We don’t look to suffer in a way that destroys our nature, and God forbid, destroys our joys and most importantly, our charity. Rather, by our sufferings we, in a spirit of docility, unite ourselves to the Passion of Christ.
Further on in his life, Saint Paul of the Cross, would write to another religious sister:
I believe the cross of our sweet Jesus has planted its roots more profoundly in your heart, and now you can sing, “to suffer and not die,” or “to suffer or die,” or, better still, “to neither suffer nor die,” but only total transformation in the divine good pleasure.
What then is the end of our suffering, or shall be the end of our suffering? We do not run to suffering in any masochistic manner, or even worse, a prideful manner. We all suffer, however. Nor do we stop at the suffering or the bearing of suffering in a participatory manner with and in the Passion of Our Lord, united intensely to Christ Crucified. No! St. Paul of the Cross says, as the cross of Christ becomes “more profoundly rooted in our hearts,” we may aspire to greater union with God, detached from suffering or death, to suffer or not, to die or not; and, thus detached we may be transformed in the “divine good pleasure.”
The above ideas come from “The Mysticism of the Passion in St. Paul of the Cross” by Fr. Martin Bialas, C.P., (published in German in 1977, and subsequently in English in 1990), p. 277-278.