Here is conclusive truth that not all get eternal life. Some, I won't argue the number but scripture says it is high, will suffer the second death which is the Lake of Fire and will NOT recieve life. John here is witnessing ALL things being made new because the old is passed away, yet still some don't get life.
Revelation 21:1Then I saw a new heaven and a new earth, for the first heaven and the first earth had passed away, and there was no longer any sea. 2I saw the Holy City, the new Jerusalem, coming down out of heaven from God, prepared as a bride beautifully dressed for her husband. 3And I heard a loud voice from the throne saying, "Now the dwelling of God is with men, and he will live with them. They will be his people, and God himself will be with them and be their God. 4He will wipe every tear from their eyes. There will be no more death or mourning or crying or pain, for the old order of things has passed away."
5He who was seated on the throne said, "I am making everything new!" Then he said, "Write this down, for these words are trustworthy and true."
6He said to me: "It is done. I am the Alpha and the Omega, the Beginning and the End. To him who is thirsty I will give to drink without cost from the spring of the water of life. 7He who overcomes will inherit all this, and I will be his God and he will be my son. 8But the cowardly, the unbelieving, the vile, the murderers, the sexually immoral, those who practice magic arts, the idolaters and all liars—their place will be in the fiery lake of burning sulfur. This is the second death." 9One of the seven angels who had the seven bowls full of the seven last plagues came and said to me, "Come, I will show you the bride, the wife of the Lamb." 10And he carried me away in the Spirit to a mountain great and high, and showed me the Holy City, Jerusalem, coming down out of heaven from God.
This is one of the passages that Universalists study A LOT!
First of all I hope you realize Revelation is a book of symbols, and is not to be taken literally. This revelation was given to John while he was in the Spirit, much like the visions we get while we are in the Spirit. And we cannot take the visions we see as being literal. They point to a greater truth, and that is what symbology means... something is given to show you a greater truth.
It is also necessary to learn what the symbology of Revelation means from throughout the whole Bible. (CLV)
"knowing this first, that no prophecy of scripture at all is becoming its own explanation." Which means of course that one verse of scripture must line up with others. One verse or the meaning of a verse/passage must become apparent in other parts of the scriptures.
So therefore, we take things like the fire of God, and look at what that means through the rest of scripture. We take the bride, the throne, the second death, Jerusalem, the Kingdom of God (and where it is) etc, and study them to see what they mean. We take the cowardly, unbelieving, vile, etc, and study the origins and why people are this way... for example, we see these things are of the flesh, and because we study the fire of God, and we study the flesh of man, we see that it is the flesh of man that gets burned up and consumed, not the man himself. btw... this process starts in this lifetime.
We also see that nowhere does it say that anyone stays in the fire endlessly.
Personally, I believe the book of Revelation to be about Jesus Christ Himself and is not necessarily a book to show us things to come in a literal worldy sense (some.. preterists, believe it's all been fulfilled). It is the book of the Revelation of Jesus Christ and takes place within each one of us. It is about the Kingdom... which is within. It is about receiving the revelation of Christ within.
I could go deeper, but I don't believe you will even accept this offering. One must operate in the Spirit to understand the things of the Spirit, not with the carnal mind.
So, the cowardly, the unbelieving, etc, etc.... will have the flesh destroyed in the Lake of Fire which is God Himself.. and His Word, which is as fire... and when WE have been cleansed of the filthy flesh we will therefore be fit for the Kingdom of God. Remember, those gates are open for the elect to go in and out of... what for? I believe to minister to those who are going through the fire of God's Word in their lives.. the destruction of the flesh. This can happen on so many levels, in so many seasons and times, that it can boggle the mind. Revelation is not a book that shows events in chronological time... much of it takes place outside of time, and within you and me... in the Spirit.