The Gospel writers share memories of Jesus talking on a number of occasions of spiritual judgment being a part of the life of everyone. (Although it is worth noting that judgment and judgmental separation play less important roles in post-Apostolic Christian writings until reinvigorated by Augustine, and that Paul himself makes very little of the matter.) The most common error made in trying to understand these remarks of Jesus is the same one made in addressing so much of what He said: we bring our ordinary, worldly understanding to Him and expect Him to conform to it.
This way of approaching our Lord can lead to cartoonish caricatures of the divine discrimination: a black-robed Jurist towering over an anxious defendant, studying the facts of the case – the Book of Life! – and then bringing the gavel down and pointing magisterially, either towards the public exit – Heaven! – or towards the divine bailiffs to take the poor soul away in chains.
This of the Jesus whose forgiveness has no limit.
The way to understand divine judgment is to abide in Christ, to dwell on how infinite love and endless forgiveness might deal with moral obduracy, using only the tools love itself could fashion or wield.
As far as I can see, the alienation from God that Jesus occasionally refers to as the consequence of leading a certain kind of life is very much like the alienation one might experience on moving to a country with a profoundly different culture. The food is different, the language is strange, the rituals and manners and customs are all very unlike those with which we’ve lived all our lives.
Those who have spent time in a radically foreign culture or who have read about the experience will understand what I’m referring to. There is an absolute sense of being an outsider, a stranger in a strange land. People regard you with bemusement, act towards you with impatience sometimes, sometimes with special generosity, sometimes with pity, but always with the awareness that, whatever else may be true of you, you don’t quite belong there the way they do, the way someone born and raised there does.
That’s the sort of separation Jesus is talking about. The heaven from which He came and which He teaches about will be an extremely foreign environment to those of us raised in this world, imbibing from birth this world’s culture, comfortable with and even proud of this world’s problems and our responses to them, accustomed to thinking and finding reward and, yes, judging, in this world’s ways.
Being born again is like being a foundling in a foreign culture.