Jesus went around healing people by the thousands. If he was able to do that, why hold back at all? Even though we accept that illness and suffering are the result of original sin, that God does not make us suffer, yet he holds the cure to all our suffering and can end it at any moment. So why does he let us suffer? It might be our fault; it is our fault, but still, how could God, who loves us, look on and see our pain without granting healing?
Certainly God could by a certain miracle suddenly remove all bodily suffering in the world by healing everyone who is sick or injured, but what then? People will be injured or sickened the next hour after the miracle. If the greatest good that could be achieved in this life was a mere removal of suffering, then God would do that every hour of every day, but we are made for something more. We are made to live the life of the blessed forever.
Death is not the greatest evil. Suffering is not the greatest evil. The greatest evil is a separation of our souls from God. Just as we will gladly undergo painful surgery with the hope of lasting benefits or endure the pain of exercise with the hope of stronger bodies, we should not fear the suffering of this world but rather hope that it will prepare us for the next. Our own suffering often accomplishes the real purpose of living.
Why does God permit the suffering of this world? We know why. Why does a parent permit their child to be stabbed with needles or have a tooth pulled? Because allowing some suffering now prevents greater suffering later. This does not take away our need to serve those who are suffering. It does not mean that we can forget about the suffering in the world, especially the suffering created by our own choices. It means that suffering can be necessary and can result in good.
Suffering is always evil but suffering can lead to compassion, endurance, patience, and humility and these are great goods. If all Jesus wanted to do was stop all suffering, there was no need for him to become a man and dwell among us; God could have done that at any time, but since he knew that permitting suffering was necessary in a world with sin, he instead came down to suffer with us.