Why didn’t God just kill the devil?

The question came from my teenage son, but it’s the kind of thing that might occur to a child of almost any age.

A rudimentary understanding of the Bible tells us that it’s the story of God’s redemption of humanity, and that the need for this comes when the devil, depcited in the form of a serpent, tricks Eve into eating the forbidden fruit and sin enters the world.

And so the question comes: so if God is all powerful and all knowing why doesn’t he foresee the problem with that pesky fallen angel, take him out, like any self-respecting deity would do, and save us all a whole lot of grief?

Let us look at a biblical understanding of the devil and how we might answer.

Who is the devil?

It is clear that the Bible sees the devil as a real unseen angelic being opposed to God. Scholars differ on how they interpret some of the statements and imagery surrounding the devil. Some see prophesies about human leaders as depicting the devil - see Isaiah 14:4-15, Ezekiel 28:11-1).  But there is a consensus that believes that he was a chief angel who set himself up in opposition to the living God and is expelled from heaven as a result taking a third of angelic beings with him (Rev. 12:7-11.  

Some posit that this takes place prior to the creation of the world and so this gives added poignancy to the devil, in the form of a serpent, tempting Eve. The devil had sought to increase his own power and so might have been envious of human beings, who God had made as image bearers from the very beginning. In sinning Adam and Eve are effectively giving authority to the evil one, when they should be under God’s rule.