In the wake of the unspeakable act of violence in Boston Monday, our hearts are broken. When we see photos of the carnage, hear the testimony of those who were there, we find it difficult not to be very sad. It is only natural that both children and adults will ask questions.
Catechists and catechetical leaders have a special role to play in helping children and adults understand and deal with this tragedy through the eyes of faith. Because of our Catholic faith, we see the "Problem of Evil" differently.
We should remind them of our beliefs about evil:
Yes, bad things do happen to good people. Look at Jesus and the martyrs. None of them deserved their suffering and deaths. Indeed, their suffering was redemptive. We should unite our sufferings with the suffering of Christ. (A nice explanation of the Pauline theology of that can be found here.)
God does not cause evil or suffering. Evil occurs because some people do not listen to the voice of God but instead make evil choices. This is because God gave us free will -and because he respects us he permits us to choose. Sometimes, because of sin, we choose evil. Free will is a gift, but it comes with the responsibility to form one's conscience, through reading scripture and study of moral teaching, and to seek to follow not our own will, but the will of God.
Good will overcome evil - but not always right away. For some things we may have to wait until Jesus comes again at the end of time. All we can do for now is pray regularly in the Our Father: "deliver us from evil..." Meanwhile, we are called by our baptism to make the world a better place. We should never give up our fight for justice, to right things that are wrong, or to defend the poor, the helpless and the innocent.
Good can come from evil. The Resurrection of Jesus depended on his suffering and death. Sometimes we have to suffer pain or loss before we can accept the call to something better. As St. Paul wrote "We know that all things work for good for those who love God, who are called according to his purpose." (Romans 8:28) The Lord is near to the brokenhearted. As an Easter people, looking toward resurrection, we should never succumb to despair.
Lastly, we need to pray for those who were killed or injured and their families. We also need to pray for peace and an end to violence and hatred. Even more than that, we are called to pray for whoever did this, since Jesus told us to pray for our enemies - and indeed prayed from the Cross for those who hurt him.
For older students and adults, you might want to call their attention to the Catechism of the Catholic Church 309-314, the section on Providence and the Scandal of Evil.