Revelation 20:14 YLT
(Young’s Literal Translation)
and the death and the hades were cast to the lake of the fire — this [is] the second death

The second death is the death of death. It’s quite simple really. 

Fire is the purifying fire of God, and all are made pure by Christ. Who is not written in the book of life? None, really. All are born out of His love and into His love. Some just don’t know it yet. 

 The name in the book of life. It’s Christ and all are in Him. He is the one who overcame. We overcome by the word of the testimony, and the word is that all are in Him, and reconciled. It is finished!!!!!

If you want to be literal, then some all shall be ‘purified’ of the junk that keeps them blinded to love, and will then will know Him. It still results in the end of death. But not the ‘end’ of anyone.

Revelation is a book of symbols and is not the basis of understanding God’s ways. But it will reflect His ways, just as it has been made to reflect what are not His ways.