Satan will be cast out of heaven  -  Revelation 12:10

And I heard a loud voice saying in heaven, Now is come salvation, and strength, and the kingdom of our God, and the power of his Christ: for the accuser of our brethren is cast down, which accused them before our God day and night.

 There is coming a day when Satan, the accuser of believers, will be evicted from heaven. Previously, he was able to approach the throne of God for the sole purpose of making accusations against Christians. Due to God’s plan, he will no longer be allowed to have access and this lets him know his days are numbered, his defeat is coming, and that Jesus has overcome all that Satan attempted to do.