2 Peter 2:4 and Jude 1:6 say God did not spare the angels that rebelled against him but cast them in to hell and delivered them to the chains of darkness to be reserved for judgement of the great day. Reveletions 12:7 says there was war in heaven and angel Michael with his angels prevailed against the serpent. Genesis is not the beginning of God, but the beginning of man knowing about God. The rebelious angels left their first estate and they were cast on earth. It was here that they found Adam and Eve and tempted them. The devil and 1/3 of the angels rebelled against God. It means we are on the winning end. Jesus said in Luke 10:18, he saw the devil fall from heaven like lightining.