There are two resurrections mentioned in the Bible; one is the resurrection of the righteous and the other is the resurrection of condemnation.1
As to the resurrection of the righteous, different groups will be resurrected at different times. As to the resurrection of condemnation, this will take place only once.
As to the resurrection of the righteous, Christ Jesus was the first to be resurrected; in order that He might have supremacy in all things.2 His resurrection will be followed by all Christians who have fallen asleep in death, from the beginning of the Christian Church until the Rapture.3 Seven years later, the righteous who die during the Tribulation, plus those who died prior to Christ Jesus' death on Calvary, will be resurrected. One thousand years later, at the end of the Millennium, the righteous who died during the Millennium plus the un-righteous dead throughout the history of mankind will be resurrected. Although these two resurrections will take place at the same time (at the end of the Millennium), they are not the same; they are two separate resurrections.
At the resurrection of condemnation ( also known as the Great White Throne Judgment) all of the un-righteous dead throughout the history of mankind, will be resurrected. Their degree of punishment will be determined and they will be cast into the lake of fire; a place prepared for Satan and other fallen angels. Those in the lake of fire will be in torment day and night for ever and ever .4
1 (John 5:28-29; Daniel 12:2; Luke 14:14)
2 (Colossians 1:18)
3 (1 Thessalonians 4:13-17)
4 (Revelation 20)