Many Catholics believe from the Bible that God must have a reason for allowing evil&suffering, but humans cannot understand it.
so the corerct response is to follow the the example of Jesus&fight against evil&sufferingas Jesus did by praying for those who suffer&helping those who suffer.
Many Catholics become doctors, nurses, social workers to reduce the amount of evil&suffering in the world.
Many Catholics claim that by giving humans free will.
God created a world in which eveil&suffering will come about through humans misusing their free will.
so evil&suffering is a problem caused by humans not God.
Many Catholics believe that the evil&suffering involved in this life