In the gospels (Matthew, Mark, Luke and John – the first four books of the New Testament) there is reference to a devil.
Its name is ‘Satan’, which means ‘enemy’.
In the 11th Century, Thomas Aquinas said that Satan was an angel who had rebelled against God.
Aquinas claimed that Satan had been one of the highest angels who had become proud and led other angels in the rebellion.
As a result, Satan and the other angels were thrown out of Heaven and Satan has opposed God ever since.
Christians may give one or more of the following answers.
God has given people free will. He has shown people how they should obey the Ten Commandments and follow Jesus’ life and teaching. It is then up to human beings to decide whether or not to follow God’s instructions.
God has a plan for people’s lives that they may not always understand. This may include evil and suffering, but Christians should trust and have faith in God’s plan.
God wants people to follow the example of Jesus and help those who are suffering. Christians also pray for those who suffer and try to help them.
Evil and suffering in this life is a preparation for Heaven. Evil and suffering give humans a chance to become better people and improve their souls. Christians believe that God will reward them in Heaven.