I now rejoice in my sufferings for you, and fill up in my flesh what is lacking in the afflictions of Christ, for the sake of His body, which is the church –Colossians 1:24

Now, as Christ, the head, had a certain amount of suffering to endure, so the body must also have a certain weight laid upon it. Our afflictions are the sufferings of Christ mystical, the sufferings of Christ’s body, the sufferings of Christ’s church; for you know that if a man could be so tall as to have his head in heaven and his feet at the bottom of the sea, it would be the same body, and the head would feel the sufferings of the feet. So, though my head is in heaven, and I am on earth, my griefs are Christ’s griefs; my trials are Christ’s trials, my afflictions, He suffers.

“I feel at my heart all Thy sighs and Thy groans,
For Thou art most near me, my flesh and my bones;
In all thy distresses, thy Head feels the pain,
Yet all are most needful, not one is in vain.”

The trials of a true Christian are as much the sufferings of Christ, as the agonies of Calvary.

Still you say, “We want to discern whether our troubles are the trials of Christ.” Well, they are the trials of Christ, if you suffer for Christ’s sake. If you are called to endure hardness for the sake of the truth, then those are the sufferings of Christ. If you suffer for your own sake, it may be a punishment for your own sins; but if you endure for Christ’s sake, then they are the trials of Christ… So, dear hearts, go on, go on; and if ye suffer for Christ’s sake, they are Christ’s sufferings.  ~ C.H. Spurgeon

http://www.blueletterbible.org/Comm/spurgeon_charles/sermons/0013.cfm