Revelation 20:10

The devil is cast down into the lake of fire and brinstone where the beast and false prophet were already being punished. (Revelation 19:20) Since the harlot was burned and the smoke goes up, it might be said all the forces of evil reap the same reward. Thayer says the word torment means, "to vex with grievous pains (of body or mind)". A double plural is used here to indicate time that goes on and on. It is like a repeating number in math. Thus, we could put for ever and ever and ever, etc. God will never be through punishing Satan for what he did. The everlasting fire was prepared for him and the angels that joined him in rebellion. (Matthew 25:41) Note the word translated "everlasting" and "eternal" in Matthew 25:46. Therefore, it could be said the reward of the faithful will only go on as long as the punishment of the wicked continues.