Resurrection, the first
'The first resurrection,' mentioned in Revelation 20:5, 6, does not mean a first resurrection, but the essence and primary part of resurrection, which is salvation and eternal life. There is only one resurrection to life. A second does not happen, and is not mentioned anywhere in the Bible.
(Reference: Apocalypse Explained 6; Apocalypse Revealed 851; Revelation 20:5-6)
Matthew 19:5
5
And said, For this cause shall a man leave father and mother, and shall cleave to his wife: and they twain shall be one flesh?