It is not down to us to question God, only he understands and who are we to question him?

    Their faith is being tested by God.

   Evil is down to the activities of Satan (The Devil) in the world.

   We are being punished because of original sin - the sin of Adam & Eve going against God.

   Sin and suffering are inevitable if we are free to choose our own destinies (freewill).
       Some people will make the wrong choices.

   Through suffering people grow and develop spiritually.

  If Jesus was able to suffer for us on the cross, then we should be able to attempt to cope
       with our own sufferings. God shared in our suffering through the suffering of his own
       son Jesus.