The Church pastors tell us to join our sufferings to Christ. This is backwards. What am learning is that Christ joins His sufferings to ours. I first had an inkling of this when I had cancer.
What do I mean? The Child in the stable was cold. He did not need to come down from heaven and join into that cold, a result of Original Sin, as the Fathers tell us that Adam and Eve would not, before the Fall, experienced pain in harsh weather. But, as Joseph and Mary adored the Holy Babe, they must have been amazed at the power of God being set aside, diminished, ignored, completely made subservient to pain and suffering.
In Mel Gibson's The Passion of the Christ, there is a particular statement of Mary, the Blessed Mother, at the foot of the Cross. She states something like, and I paraphrase (apologies if out of order), "Jesuah, Bone of my bone, and Flesh of my flesh, let me die with You." At that point, Christ gives Mary to John and to us.
She is the co-redemptrix and the scene indicates such. But, Christ, Who dwells in us, redeems our suffering daily. As we carry Him into the world in suffering, frustration, physical pain, He is there joining us in those results of sin. He decided to do that. We do not join with Him, He joins with us, in us, and raises us up into a relationship of love because of that joining. I am never alone in my suffering, as Christ is with me. I know this. \It is not merely my Faith which tells me this, or the great teaching of the Church, which explains my baptismal union with God in His Trinity. I know this. When one is with Christ, nothing else matters. This is why Mary wanted to die; not merely to end the nightmare of the Crucifixion which she witnessed, but to be with Christ, her beloved Son. The lay person does not need to seek crosses, as these are given and to some of us, in number. It does not matter. What matters is that we each recognize the Crucified One in our own hearts. He is there.