Matthew Henry Commentary Revelation 20:4-6

"And I saw thrones, and they sat upon them, and judgment was given unto them: and [I saw] the souls of them that had been beheaded for the testimony of Jesus, and for the word of God, and such as worshipped not the beast, neither his image, and received not the mark upon their forehead and upon their hand; and they lived, and reigned with Christ a thousand years. The rest of the dead lived not until the thousand years should be finished. This is the first resurrection. Blessed and holy is he that hath part in the first resurrection: over these the second death hath no power; but they shall be priests of God and of Christ, and shall reign with him a thousand years." — Revelation 20:4-6 (ASV)

Here is an account of the reign of the saints, for the same period as Satan is bound. Those who suffer with Christ will reign with him in his spiritual and heavenly kingdom, in conformity to him in his wisdom, righteousness, and holiness: this is called the first resurrection, with which none but those who serve Christ and suffer for him will be favored. The happiness of these servants of God is declared.

No one can be blessed except those who are holy; and all who are holy will be blessed. We know something of what the first death is, and it is very awful; but we do not know what this second death is. It must be much more dreadful; it is the death of the soul, eternal separation from God. May we never know what it is: those who have been made partakers of a spiritual resurrection are saved from the power of the second death.

We may expect that a thousand years will follow the destruction of the antichristian, idolatrous, persecuting powers, during which pure Christianity, in doctrine, worship, and holiness, will be made known over all the earth. By the all-powerful working of the Holy Spirit, fallen humanity will be created anew; and faith and holiness will as certainly prevail as unbelief and unholiness now do. We can easily perceive what a variety of dreadful pains, diseases, and other calamities would cease if all people were true and consistent Christians.

All the evils of public and private conflicts would be ended, and happiness of every kind largely increased. Everyone would try to lighten suffering, instead of adding to the sorrows around them. It is our duty to pray for the promised glorious days, and to do everything in our public and private stations which can prepare for them.