How is the devil at work in the world?

Answer 1

Satan entered post-Exilic Judaism as the 'adversary' but under the instructions of God, tasked to test the righteousness of the faithful. Jews continue to see Satan as the loyal assistant of God, rather than as the devil of Christianity. So, in Judaism, Satan does the work of God and can scarcely be called the devil.

It is in Christianity that Satan evolved to become the devil, seeking to cause the faithful to deviate from righteousness and to destroy God's kingdom. Satan continued to evolve throughout much of the Middle Ages, at time as a figure of fun and sometimes with changes in how he exerts his wicked powers. He is now an essential part of Christian belief, but if you did not read about Satan in books you believe to be true you would have no reason to think that he exists. In fact, why should we believe a being exists if we can not even decide whether he helps God or opposes him?

Answer 2

Devil? whats that?