I'm not sure what it is, but I notice a lot of preoccupation by gnostic ecclesias with their lineage and origin. I was just reading a couple of foreign language gnostics (Sucesion Gnostica Apolostica and Plerormon [caution- Loud Dead Can Dance song when you visit]), and I notice that there are long bits about the lineage and ordination of their bishops and how far back they go and etc. I'm not saying the AJC is immune to it, as we've just received a charter from another bishop and have lots of documentation for our own lineages.
We do this in the face of Evangelicals who speak to angels, Ministry training from your own home, and other flashy or even stoic preachers who have no lineage or legitimacy other than their ability to preach the word, and MAYBE a degree from a bible college. In the process of our incorporation, we've learned that you don't even need to be part of a wider church to be tax exempt. You simply need to have the word Church in your name, and do what a church does (preach, religious education, charity, etc.)
Given this, why are we so preoccupied with lineage?
Are we trying to give ourselves legitimacy? If we do the work, we're legitimate, at least as much as some of the Evangelical groups. By their fruits shall you know them.
Are we trying to tie ourselves back to a tradition? Well, yes, but the Evangelicals manage that simply by relying on the Bible. The bible is their source of tradition, that 'old time religion'.
We often tie ourselves to a past that has a bit of baggage. The Apostolic Church has had a spotty record, blamed for many offenses over the centuries. The independent bishops of that lineage also have their share of charlatans and fakers. Most folks think it's just myth anyway, going all the way back to the apostles.
So, why is it important?
Why do we spend so much time documenting it and posting it for all to see, that we have transmission from another who's walked before us?
As a priest in an Apostolic Lineage, this is obviously of importance to me. I sought out ordination in a specifically Apostolic Tradition, and was suitably impressed with and reassured by the documentation when I was shown it. But I talk to other folks about it, and I either get nods of confusion (as in "Why is this important?") or confusion ("So, like my Roman Catholic Bishop, but not?").
And none of it matters a whit towards the ministry I pursue. Homeless folks generally don't care if you're in the apostolic tradition or not, as long as you're helping them with a place to stay.
Since I'm a mystic and a magician along with being a priest, I have my own opinions on why these lineages are important, and I'll address them later. For now, I'd like to get responses from folks about why they think it's important (or unimportant and the churches spend time on it).