I’ve been thinking about the Christian concept of apostasy lately. Part of that has been because of the recent news about Joshua Harris, former Christian author and megachurch preacher, publicly leaving the faith. The other was because of my yearly visit to my parent’s church, which I make every July to celebrate my mother’s birthday. This was the first time I’d been there since I told my parents I was converting and, as has become usual, it was a bit of the elephant in the room everyone steadfastly refused to acknowledge. Appropriately, the subject in Sunday school was the one sin from which there is no repentance: apostasy.

So, a quick definition. Apostasy, for Christians, is the rejection of faith by a former believer. In the Bible, it’s frequently described as a kind of adultery (Jeremiah 2:1–3; Ezekiel 16), or as a “falling away” (Luke 8:13; 1 Timothy 4:1; Hebrews 3:12). Personally, I like the “falling away” image better, but for me it felt a little like the opposite was happening–losing my belief felt like everything else was falling away, like the structure I had built out of my faith had become unsteady and collapsed.

In Hebrews (6:4-6), it says that “It is impossible for those who have once been enlightened, who have tasted the heavenly gift, who have shared in the Holy Spirit, who have tasted the goodness of the word of God and the powers of the coming age and who have fallen away, to be brought back to repentance. To their loss they are crucifying the Son of God all over again and subjecting him to public disgrace.” The sin of apostasy as one of insult and desecration is repeated in Hebrews (10:29): “How much more severely do you think someone deserves to be punished who has trampled the Son of God underfoot…and who has insulted the Spirit of grace?“

Not all Christian denominations accept that apostasy is irredeemable, but quite a number of them–including, apparently, my parent’s church–do. So imagine my discomfort when, just a few weeks after the painful conversation where I had to admit to them that I no longer believed in Jesus (and hadn’t for quite some time), I was sitting between my mom and dad listening to an earnest young pastor discuss John Bunyan’s The Pilgrim’s Progress.

Written in the late 1600’s, Pilgrim’s Progress is the story of a dream wherein the main character, Graceless (later renamed Christian) journeys from his hometown of sin and degradation to the beautiful “Celestial City.” It’s a lot to take in, with characters named things like “Mrs. Inconsiderate” and “Mr. Fearing,” and locations like the “Village of Morality” and “The Wicked Gate.”

For some reason, my mom expressed surprised that I had not previously read this page-turner. Anyway, the section they were discussing involved Christian going through seven rooms, each of which represented an aspect of faith. In one room, there was dust all around, stirred up by a man who was urgently sweeping. Only when someone else brought in water did the room get cleaned. I’m not going to go into this here, but you get the point: every room is a metaphor. Fantastic.

Okay, so the room that shined a light on the giant elephant of my Judaism was the one that contained a man in an iron cage. He was, he told Christian, a former believer that had been seduced by all the dirty dirty temptations of a fallen world. Having renounced his belief, he could never, ever get it back.

I’m going to be honest here: the whole idea of nonredeemable apostasy was completely new to me. I had hoped that my parents could find comfort regarding my conversion by praying that it was simply a phase on my way to returning to the Christian fold. Unfortunately, it looks like this isn’t an option for them–unless they choose to diverge from their church (unlikely), they’re going to have to accept that I’m just lost. I’ve already become an apostate, and there’s no going back for me.

From my point of view, it’s a little bit of a relief. This whole dogmatic concept gives me an answer to any attempts to argue with my conversion: sorry, damage is done, nothing I can do! Look, ma, it’s right there in Hebrews.