"Children in school learn what we call definitions. A definition is an explanatory statement which tells us exactly what a certain thing is, as "an island is a tract of land completely surrounded by water." God also gives us definitions in His Word. We could cite hundreds of examples! He tells us exactly what certain things are. And in the passage quoted above God tells us exactly what the second death is. "And death and hell were cast into the lake of fire. THIS IS THE SECOND DEATH." Now let me make this a little plainer. Definitions of men can be given backward. For instance, the definition, "An island is a tract of land completely surrounded by water," can be given thus: "A tract of land completely surrounded by water is an island." This is but another way of stating the same fact. It does not, in any way, change the meaning."
"Now let us try this on the definition of the second death. The Bible states it thus: "Death and hell were cast into the lake of fire. This is the second death." Now let us turn this statement around for clarity. "The second death is death and hell cast into the lake of fire." Therefore we have exactly the same meaning either way it is stated. What is the second death? IT IS THE FIRST DEATH AND HELL CAST INTO THE LAKE OF FIRE! This fact is very important. Most Christians and nearly all preachers read the Word of God very superficially. They read and suppose that the second death is men being tortured forever in the lake of fire. Yet there is absolutely nothing in this passage about men! The verse that follows the one we are considering speaks of men being cast into the lake of fire. But not this one! It is the state of death and the condition of hell that are cast into the lake of fire. The second death is not men cast into the lake of fire, or men tormented or tortured forever. That’s not in the Book! The Holy Spirit has made it very simple and plain. The second death is the first death and hell cast into the lake of fire. That is the Holy Spirit’s definition, not mine."
Muxh more in the link:
https://www.godfire.net/eby/Rev/rev231.html
.
"And I heard a great voice out of heaven saying, Behold, the tabernacle (dwelling place) of God is with men, and He will dwell with them, and they shall be His people, and God Himself shall be with them, and be their God. And God shall wipe away all tears from their eyes; and there shall be no more death, neither sorrow, nor crying, neither shall there be any more pain: for the former things are passed away. And He that sat upon the throne said, Behold, I make ALL THINGS NEW. And he said unto me, Write: for these words are true and faithful" (Rev. 21:3-5).
"Whatever we hold as the nature of the death state, may we let this truth sink deep into our hearts: DEATH IS TO BE ABOLISHED. The ringing declaration, "The last enemy that shall be destroyed is death," overthrows the whole structure of accepted, but unproved, theology which shuts up the mass of the human race in "eternal death." When the "last" enemy is destroyed, abolished, it is self-evident that none remains. Those wretched religionists who demand the endlessness of death, who argue for eternal torment in the lake of fire, the second death, do err, not knowing the scriptures nor the power of God. The lake of fire must end because death and hell are cast into it, which is the second death, and in the end THERE SHALL BE N-O M-O-R-E D-E-A-T-H. No more death! No more first death. No more second death. No more of any kind of death. To say there is no more death is to say that there is no more sin and no more sinners, for sinners are dead men, and the wages of sin is death. To say there is no more death is to say that God has not "burned up" all the wicked and left them dead, or in hell, for as long as any creature of God is in a state of death, death is not abolished — its power still reigns. To say there is no more death is to say there is no more hell, for hell is "the realm of the dead." To say there is no more death is to say there is no more a lake of fire, for the lake of fire is the second death. What a universe of truth is contained in three little words: NO MORE DEATH!