Suffering - yes, it is a mystery. Yet if we wish to share in the glory of Jesus' Resurrection, we must be prepared to accept what He accepted - suffering for the sake of others in union with Jesus. All He did was for others. That's where suffering begins to make sense.
Jesus -- the Son of God -- was willing and eager to share in our sufferings. He experienced all of them in His flesh. Some might be tempted to say, "Suffering is evil -- the root of all evil." But that was what Peter thought when Jesus told him he would suffer, be crucified and die, and on the third day be raised again. Jesus rebuked Peter abruptly, and told him what was truly evil: "Get behind me, Satan".
No Cross, no Resurrection - no dying to self, no new life in Him.For the majority of souls, self-will, self-love asserts itself: "My will be done, not yours, Lord." We are not willing to embrace suffering. We are not willing to be generous with our suffering and offer it for the salvation of souls, as Our Lady at Fatima lamented.
Most souls will not be ready to see Love in His Absolute Purity and Goodness. We have been blinded by our own selfishness, and have fallen for the ancient temptation 'to be like gods'. We want our way.
Most souls will to go to purgatory - to be cleansed, to be purified. One account, in particular, highlights this desire. St. Gertrude saw, in a vision, a very devout nun standing before Our Lord, but was unable to gaze at His Face. She backed away as He beckoned her to come. When the Saint asked her why she did not go to Him, she replied that she was not yet cleansed of every stain left on her soul by her sins. She knew she was not pure enough, and wanted to be purified. She chose to be purified in purgatory.
God is Love -- and if He suffered, and if we wish to call ourselves Christians, His followers, we must do the same, for the same reason. Blessed Mother Teresa once said,"when suffering comes to us, we should accept it with a smile, because it is the greatest gift that God gives us. It is a gift to have the courage to accept everything that He sends us."
The choice is ours. We can love now, as He loved, and willingly accept and offer our suffering for others. By doing so, we will show our love for Him and gain great merit. Or we can wait, and have it imposed later, by purifying necessity, with no merit.