One student recently suggested that there might be a progression in the Gospels from earlier books that are more this-worldly in focus to later books that are more “mystical.” I don’t think I’d agree that the later Gospels become more mystical, if by that you mean more “other-worldly.” On the one hand, I think all three of the Synoptic Gospels (Mark, Matthew, and Luke) reflect essentially the same view of the Kingdom of God. That Kingdom is a holistic reality that includes physical, social, political, and spiritual aspects. It will only be fully realized in the resurrection, but it is manifested in “glimpses” in the present through the actions of Jesus (and his followers). I think that setting up a “this-worldly/other-worldly” polarity doesn’t do justice to the way these things are held together in all of those Gospels. One key is recognizing that the fully-manifested Kingdom is not located in heaven, it’s located on the renewed earth after the resurrection. This is even true in John. The “dwellings” that Jesus goes to prepare in God’s house for the believers aren’t permanent homes in Heaven, but temporary dwellings in the heavenly temple where believers will wait for the resurrection. So Kingdom life is always a holistic life in the Gospels.
If there’s a contrast, then, it’s between the Synoptic perspective on the Kingdom and the perspective in John’s Gospel. But if we read John carefully we will notice that even John isn’t talking about a spiritual escape from earthly existence. “This world” in John isn’t a place (and isn’t this planet) but rather a pattern of life. It’s a pattern of social, political, and spiritual living that is violent and opposed to God. The Kingdom in John does involve being rescued from “this world” and moving into a “heavenly” existence. But it’s not escaping from this planet and going to heaven. It’s escaping the current (fallen) dominant pattern of life and beginning to live a pattern that finds its origins in Heaven. It’s life lived the way Heaven (i.e., the creator God) intends. So what sounds at first like a very dualistic, other-worldly faith in John turns out to be just as holistic as in the Synoptics. It’s just that the language used to express it can be misleading.
The other factor to keep in mind in John is that his interests are much narrower than the interests of the Synoptics. John says very little at all about ethics, about how believers are to live their lives. This isn’t because John didn’t think ethics were important. In fact he equates “loving one another” with having faith in Jesus. But John’s Gospel isn’t designed to teach us how to love one another. It assumes that we already know how. Instead, John is focused much more narrowly on the existential decision we have to make about who to trust–Jesus or human authorities. This is, I think, because John was written in the midst of a much sharper conflict between the local synagogue and the nascent Christian community. The believers were getting the overpowering message from the synagogue leadership that they had been led astray, that Jesus was a deceiver. In response, John has to present just as powerful a message that in fact the believers were right to trust Jesus above anyone else. But because of that strong agenda in John’s Gospel he’s just not spending time on teaching us how to live as Christ-followers. He’s focusing on a stark either-or decision and calling us to make the right one.
All of this means that I don’t think there is any progression in the Gospels toward a more other-worldly faith. After all, Luke was the second-last Gospel to be written. All of the Gospel writers view the Kingdom of God as a holistic reality that encompasses social relationships, political relationships, physical needs, and our relationship with God. It’s just that the specific interests of the various writers lead them to focus on some aspects of that holistic Kingdom more than others.