R.C. Sproul answers this question: Can suffering in general rather than suffering for our Christian faith be counted as sharing the sufferings of Christ?
I think it can. If the suffering is done in faith – that is, throughout the suffering we place our trust in God – then I think we are participating in the sense that we are willing to suffer and to trust God in the midst of suffering, even as Jesus trusted the Father. . .
In regard to the man born blind (John 9), the question was asked of Jesus, “Who’s sin was it, this man’s or his parents’, that he was afflicted with blindness?” Jesus said it was neither. In other words, the question was a false dilemma. And those who asked it were trying to reduce to two options something that had more than two. There was another option. Jesus said, “It wasn’t because of his sin or his parents’ sin. This person was born blind so that the power of God and the grace of God may be made manifest.” That person was suffering not from persecution. His suffering was used by God to bring honor and glory to Christ.
I mention this instance because it is a clear biblical case in which suffering has theological value – not merit, but value – insofar that it is useful to the purposes of God. Christ himself tells us that we are going to have afflictions and suffering in this world. He certainly indicates that we are going to suffer persecution, and he gives a particular blessing to that in the Sermon on the Mount, saying that the reward will be great. He also indicates that there will be other kinds of suffering that come our way and that we are suffering in him and with him.
R.C. Sproul, Now, That’s a Good Question, pp. 473-475