Most suffering are the consequences of sin being visited upon us. Spiritual laws, like laws of gravity have automatic consequences when broken.
But God works all things out for good to those who are called according to His purpose. (Romans 8:28), and often God will use trials to build within us His character. For His strength is perfected in our weakness, for the witness of The Lord is made manifest in accomplishing His Will through our frail, weak selves if we would but be obedient.
It often does not seem fair to us. Same as a child who cannot see the end result of what a parent is preparing for him some years down the road. No, the child cannot have a chain saw at age 8, even though he cries for one. But in time, with training he will be ready to have one and be able to use it with skill and without risk to himself or others. That is a physical analogy to a spiritual truth we cannot yet see.
The suffering and slaughter of Christians in this evil world may not seem fair to us. God is often testing to see if we will hold onto our faith in Him, or if we will buckle and give up to do things our own way.
I think the more OUr Father in Heaven allows us to suffer trials, the more He is perfecting that person for the Office Jesus Christ is preparing for them to inherit for eternity.
We have to trust God. We must trust that no matter the physical issues, our spiritual life is what is most important to God. He who began a work in us will see it to completion, and often that requires us to overcome everything this rotten physical flesh has to dish out.
I agree but it is not always an easy thing to discern....some things have nothing to do with our choices...like the body aging, something we cannot escape from. Other times it's like a boomerang..it comes back on us. Giving thanks is not easy but I have learned to thank him when I don't understand because he knows what these things or happenings are and what purpose he will make of them.