The "Inescapable Love of God," by Christian philosopher and California university professor Thomas Talbott, is a solid treatment on the subject of 'ultimate reconciliation' or Christian universalism - the belief that in time, over the 'aions' (eons = ages) - whether on this side of death or the other - ALL people - past, present, and future - will eventually be saved or reconciled to God. After all, the Bible does say that in the end, "Every knee shall bow and every tongue confess that Jesus Christ is Lord." [There are many, many other "ALL" statements in the Bible about salvation and God's 'reach' - feel free to look them up yourselves]. Christian universalists believe that even after great duress and after great chastisement, if necessary, the most wicked and hard-hearted will eventually and finally accept God - come to belief in His Son - and do so willingly. But universalists recognize that this acceptance/repentance can happen even AFTER one dies, though exactly how and when is not knowable for us on this side of the veil.
Talbott's book is both scholarly and accessible to the average, every day reader. Again, 'Christian universalism' is the belief that, although for the unbeliever there does await after death an experience of painful chastisement and it is not something anyone would knowingly want to suffer, it does have a Godly purpose (remedial, corrective, purifying) rooted in God's love for us and it is not, contrary to popular belief, forever (though it may very well feel like forever). Some people are under the mistaken impression that Christian universalism is the belief that there is no 'hell' or 'Hades'. This is not correct. Also what is incorrect is the mistaken belief stemming from many (not all) of today's English Bible translations' use of the Greek word 'aionion' was correctly transposed by later Bible translators as meaning 'eternal' and that the word 'eternal' (from the Latin 'aeternus') means forever, endless, infinitely. Whether 'aionion' from the Greek or 'aeternus' form the Latin, the word incorrectly translated as 'eternal' does not mean 'forever' in either case. And although there is a TON of scholarly treatments on this subject alone (be prepared to 'go deep' on the subject or don't go at all!) - the meaning of the Greek words aion, aionion, etc. - the reader can go into all that on their own, and I would recommend it if you believe in 'unending torment' as I once mistakenly did. Anyway, Talbott's book amply covers that subject, as well.
I HIGHLY recommend this book as well as Gerry Beauchemin's book on the same topic,
"Hope Beyond Hell." Although I was never really satisfied with the faulty 'endless/forever' translation and use of the word 'eternal' where it often should not have been used in the Bible - the Greek, Latin, and English Bibles were translated by men who, being flawed humans, did not have complete access to ALL (or as much) of the ancient linguistic information we now do - and, to be honest, some of them had 'less than honorable' agendas, or at least beliefs that were slightly skewed/flawed/biased. Sadly, because of the Bible mistranslations and much of the church's sometimes schizophrenic or abusive teaching on this serious subject, it has caused much confusion and unnecessary pain and fear for many people over the millennia.
But universalism was the basic belief and teaching of the vast majority of Christians up to about the 4th and 5th centuries AD. You would be surprised how many well-known and respected Christian teachers/writers/preachers over the centuries were actually universalists, but unfortunately, you don't hear a lot about that these days. Their voices were drowned out by the more powerful, it seems.
For myself, for several years, I have been unsatisfied and somewhat ambivalent about the commonly accepted teaching on a forever, endless hell fire. But in recent months, I have had a change of heart and mind and it has really been a much welcomed life changer! God is LOVE, just as the Bible says. To be clear, like all classic Christian universalists, and as the Bible teaches, I DO believe there DOES await an unimaginably UNpleasant experience of separation from God - popularly called 'hell' in English - for anyone who, despite being lovingly informed to the contrary while on earth, has still rejected or even hated God and His loving offer in his son Jesus Christ, regardless. But this choice of destination is OURS, not God's choice for us. And as Jesus said of those who are sent there, "I assure you, you will not get out until you have paid the last penny."
But, only by God's grace and the help of a couple of good Christian friends, I've come to now understand that, as horrific as that place/experience will surely be for the unbeliever or God-hater - and no one should ever WANT to go there and experience it, at least there IS a 'last penny,' there is an end to it.
In John's Revelation of Jesus Christ, it is written that Jesus 'holds the keys to death and Hades' and it is Jesus who will destroy them BOTH in the end (and if there will eventually be no more death and no more hell, where will all those who have been in hell go or be? The answer: with the Lord forever) But until then, the 'hell' experience is allowed to teach us - because many of us will need to be taught - that God truly IS love and that he IS - and always has been - our very Life and Source, which is a truth we stubbornly may not have believed while living our short lives here on earth. How long is hell? The Bible is not not clear and I think this is deliberate. The Greek word 'aion' and 'aionian' always refer to time (not a timeless, endless 'now' as is mistakenly believed). The 'time,' so to speak, will likely be different for each person, both qualitatively and quantitatively. Call me a heretic, if you wish, but I am a Christian universalist and am never going back. ;)
Talbott's book is excellent. As a brilliant and seasoned philosopher of faith, he uses syllogism to devastating effect showing how both the Calvinist and the Arminian positions are false, leaving only the universalist position as the true. As Talbott illustrates, the Calvinist believes God is sovereign and all powerful, thus he CAN save everyone if he wants to, but for some reason chooses not to. The Arminian, on the other hand, believes God is ALL loving and desires everyone to be saved, but he is not powerful enough to do so! Thus, the Calvinist God is powerful but mean-hearted, saving only some and letting the rest go to hell 'forever.' The Arminian God is all loving and desires only our good - the good of all people - but he is too weak to bring salvation about for everyone. However, the universalist position shows scripturally God to be both ALL powerful and ALL loving - He loves ALL people and will bring EVERYONE to salvation, over the course of time, whether on this side of the veil of death or the other side. Yet he is just, fair, and impartial, i.e., there is the classic and oft-quoted example of the evil Adolf Hitler, for instance: yes, even he, too, will eventually be granted salvation, but not without first undergoing unimaginable sufferings in 'Hades' for his crimes. For how long and what that is like for him, we cannot know - we can only imagine. But we must all remember that we are ALL sinners and our sin - any sin - is an 'abominable stench in the nostrils of God,' to use an ancient analogy from scripture. NONE of us deserves heaven or endless life in God in our own merits, but may only gain it by the merits and accomplished work of the Son of God and his sacrifice on the cross for us all. God really IS love. Love is essential to His very nature. It's who He is. 'God is love' (1 JN 4:16) is not just a 'nice saying.' If the universalist position is false, as many Christians believe today, it means that the God-created Adam and his sin was more powerful than the Son of God - God in the flesh - and his saving work for us on the cross. I simply don't believe that. Do you?
Lastly, I have gained a new understanding of Jesus' warning: "Judge not, lest you also be judged. For the measure with which you judge shall be used to against you." Here the Greek shows 'judge' to mean 'condemn.' So, do not condemn others. For no matter how long it takes and how we may eventually get there, we will ALL end up in the same place, with the Lord God through Christ Jesus, for "there is no other way by which men may be saved." And many of who think they are going to heaven may not be, at least at first. Therefore, do not condemn others but also take careful heed to the Lord's warnings - as well as encouragements - about the afterlife. It is a serious matter, more serious than we may know. Also, the parable about the vineyard and the workers going out at the 6th hour, 9th hour, etc. in Matthew 20 has a new meaning to me now. I have a very interesting and surprising understanding of that parable now. Many other verses have taken on a whole new meaning and new life. Very exciting, very encouraging!