We can hear that question every day. "So, why do bad things happen", or what some ask, "why does God let bad things happen?"
God does not let them happen. But, because of original sin, God knows that bad things will happen and yet He can turn them around for good...for His good which is for all our good. This, we may not, from the perspective of this world, understand. What we know is that God suffered far more than anyone has or will ever have. Jesus Christ came into this world to show us that the only escape of this fallen world with all its sin is death. God gave us free will, and He acknowledges our choice and He allows us to experience the outcome of our choices, trouble and suffering is part of that.
Effectively, we are blessed even when bad things happen. How? When we give ourselves to Him, trusting in Him that good will ultimately reign when the bad things happen, then we are blessed. Trusting in Him to turn things around for His glory which is ultimately ours. We know this to be true as His Word promises.
Now, someone can say, "Well, my brother never chose cancer or my son never chose to be killed in a car accident." Our remote ancestors Adam and Ever made a decision that affected every person born since then as well as nature itself. We put a curse on ourselves and the world because we choose to disobey God, the curse is 'corruption' which means that the world is now operating in a way that it was never intended to.
Cancer is a result of this world because our body is not able to function in the perfect way that it was intended to. An accident is also the result of our being in an imperfect corrupted world.
Did Jesus's coming really change that circumstance as in create an 'out'...? Yes, by accepting Jesus' as the new Adam a new kind of man as in 'reborn' (God in the flesh - born to die and be resurrected) we are able (being born again -baptized) to be changed on the inside with the expectation of the outside being changed soon along with the restoration of the earth and nature as it was before the fall of man.
This world is a fallen world. Jesus reminded us that though we are in it, we are not of it ~ John 15:18. In Him, we overcome this world, through death of this world and resurrection in Christ.
What about prayer, don't some people pray and actually experience miracles? Yes, that can happen. We can call on the Holy Spirit to help us overcome this world and ask if that is God's will that a person remain with us, he/she will be healed; because, by God the Holy Spirit's intervention His Will / His Glory will be revealed and recognized. And, sometimes, God shows another way to overcome this world and that is through death which is also His good as such it also reveals His Will/Glory arriving at the same result... which is "...he who has the Son has life; he who does not have the Son of God does not have life."
"For anyone born of God overcomes the world. This is the victory that
has overcome the world... anyone who believes in the Son of God has this
testimony in his heart. And, this is the testimony - God has given us
eternal life, and this life is in His Son. He who has the Son has life;
he who does not have the Son of God does not have life." 1 John 5