I posted my rhetorical question on one’s citizenship being “in Christ” (or, the Kingdom of Heaven, properly speaking) in a Facebook group. This generated the following dialogue.
Howie Dyano:
Interesting analogy. A question, though: how do we distinguish apostates from those in the faith using the framework of your analogy?
Tom:
I’m not certain what you mean, so apologies if I don’t hit it dead on.
The etymology of “apostate” actually works hand-in-glove with this analogy. https://en.m.wiktionary.org/wiki/apostate
A Christian is one who simply remains in the Kingdom of Heaven that Christ the High King has called them into (the zip code they were baptized into). His work; we’re just the peasants who have the good fortune to be part of it.
An apostate is one who fils out a change of address form to transfer to a different zip (paganism, atheism, etc.). Their work.
Hence, you have monergism without double predestination.
Identifying apostates can be hard if they don’t wear it on their sleeves. But the distinction between them and Christians is easy: in Christ’s zip, or not.
Howie Dyano:
Tom… My question meant how does one know there zip code is in Christ? An apostate was baptized, too, after all. Is it possible one who shows desire to be in Christ and sincerely fears God is? I’m trying to distinguish how two people who were baptized can distinguish true faith without looking to themselves. Are you saying those who are apostate are only those who consciously confess something other than the Christian faith?
Tom:
“I’m trying to distinguish how two people who were baptized can distinguish true faith without looking to themselves.”
I’m not sure that goal can be endorsed by scripture. Matthew 7 is instructive here. Why would Jesus mention knowing false teachers by their works if looking at what people do is not an admissible indicator of their “residence” so to speak?
“Are you saying those who are apostate are only those who consciously confess something other than the Christian faith?”
No, and this gets at Matt 7 again with the many who will say “Lord, Lord.”
So here’s the rub, from the standpoint of my analogy:
I just gassed up and had to use my zip code. Suppose I had moved, but not changed my address on file with my bank – I’d still need to put in my old zip to complete the transaction.
Suppose further that I kept using my old zip on letters and shipping labels.
Over time, the disparity between my proclamation of a non-applicable zip and the reality of my living situation would start to become very noticeable.
Not getting bank statements. Not getting my Amazon packages. No one returning my letters.
I profess to live at zip code X, but when I park my car for the night it’s at zip code Y. (These people punch my zip code in with their fingers, but their domicile is far from me.)
This inconsistency, this “out of sync” situation that exists as a result of me professing one reality, but living according to something else, should tip me and anyone watching off to the fact that, no indeed, I don’t live in the zip code I profess to.
Hence, according to this example/analogy, I would be an apostate.
Thanks be to God that he’s still got the Keys to my old domicile in zip code: Christ, and I’m welcome to move back in even though I left the place pretty messy.

