The Devil, Satan, was chained and thrown into the Abyss by the suffering and death of innocent Jesus on the cross, and then by Jesus's resurrection. He may be up out of the Abyss, because the end times are near. It's a little like when a prisoner who is to be executed is taken out of his cell (the Abyss), and led down the hall to the execution chamber.
For Satan, the execution chamber is the lake of fire. Those people who do not accept and believe in Jesus's salvation for them, will be thrown into the lake of fire along with Satan and his fellow, evil angels.
The lake of fire is the dissolving of this universe because it has been corrupted by Satan's existence in it. It will be replaced by a new universe, including a new earth. The lake of fire, the dissolving of this universe, will essentially take forever to be completed. Why? Because Satan is powerful enough that he can constantly shrink himself to avoid entire, instantaneous destruction... shrink himself ever and ever smaller without being destroyed.
At any time, Jesus will return to finish all of this, and to take His people home to the new universe. For each person, the return of Jesus will come when the person dies. Why? Because the last thing a person will see in this life ends at the persons death. The next thing he will see is Jesus calling him to life from the grave... calling him to the judgment, to determine his position, the lake of fire with Satan, or the new universe with God.
Whoever you are, stand in your heart with Jesus so that you get the new life in the new universe. Get info about all this in the Bible, especially the New Testament.