The Bible teaches that the existence and activity of demons will continue until the Second Coming of Jesus Christ. In fact, it suggests that demonic activity may increase up to, and during, that time. However, the fate of demons has already been decided according to the Bible. Their irreversible sentence unto eternal punishment was sealed when Jesus died on the cross and rose from the dead three days later, forever defeating sin, Satan, and demons. Although Satan and demons have been "sentenced" they have not yet been "locked up." That part of their punishment will come at the end of time. (Learn more about Jesus Christ here and the end times here.)