1
Flawless Morality
A perfect religion should be grounded in flawless moral values, like supporting animal rights, gender equality and same-sex-marriage and clearly condemning slavery, racism and sexual abuse.
Torturing someone for all eternity who has never heard about your faith isn't morally acceptable, there's actually nothing that would ever justify doing so much harm.
2
Encourage Critical Thinking
Many religions make you choose to 'believe' and reject critical thinking, logic and reasoning, but these are the things we use for working out what's right and what's not. How else would you determine that you're correct, if not by questioning your viewpoint?
3
Explain The World We See
Many religions claim there's one omnipotent and inherently good god, but the world we see is not what we'd expect from such a deity. A perfect religion would have to explain why all this death, harm and chaos exist in our world.
4
Contain Relvant Information
A holy book should contain relevant information, rather than just a bunch of horrendous stories about people that may or may not be part of a raiding tribe.
How about containing clearly structured information regarding how to become a better person and how to build a peaceful society?
5
Exist Since Ancient Times
Shure, we could simply make up a modern religion fitting these criteria, but then we would know it's made up. Why would a deity wait to reveal himself or herself until now?
6
Originate In Multiple Places
We wouldn't expect a perfect religion to be known to only one tribe for thousands of years but rather be present all around the world, even very long ago.
A good god doesn't simply choose a tribe at random and tell them they're superior to all the others. That's exactly the sort of thing that a tribe would make up to justify feeling superior.
7
Persist Throughout The Ages
We would expect the perfect religion to have always been one of the dominant ideologies. If a religion is right it surely must be popular and it also shouldn't change throughout history.
8
Prove It Wasn't Simply Made Up
Let's say the holy book would tell you about something so scientifically advanced that it couldn't have emerged from the ancient people who wrote it down.
Even if a new religion suddenly emerged with consistently Flawless Morality that Encouraged Critical Thinking, Contained Relevant Information and could Prove It Wasn't Made Up, it would still be a new religion and couldn't have existed for ages whilst being reasonably popular throughout history.
Otherwise you would already know about it, would you?
Origin Of The Ahura Yasna
The first holy book (which we call the the "Ahura Yasna") is known to the Zoroastirainis as the "Gathas". They claim that it originates in Persia where Darius I. popularized it, but there's a few reasons to conclude it's a lot older than that.
Accoding to Ammianus Marcellinus, Hystaspes, the Father of Darius, learnt about this faith from the Brahmans after traveling to upper India.
Those people may have belonged to the Ajivika faith since both them and Darius are constantly depicted with lotus flowers, one of the faiths that passed on this holy book alongside the Jains and Bhuddists (+ tisya = Tishtrya).
Indian Emperor Ashoka promoted the ideas of this book and we can see a strong connection between him and Darius in Dharma Holidays and the Zoroastrian Tishtrya.
At the time of Ashoka, there already were a couple of faiths based on this holy book, but most people didn't have access to the exact contents and so people started mixing in their own ideas.
Later Mazdak strived to restore the original faith whilst some of the core ideas of this religion became intrinsic parts of most of the popular modern religions.
However, clearly God had different objectives than having a large following of these exact teachings at all times.
Persian / Indus Valley Origins
Many other translators assumed the texts to be of Persian, not Indus Valley origins - as modern Zoroastirainism originated in Persia -, disregarding the histrorical linguistical evidence and connections. This results in many words being translated with their more modern Persian translation, rather than their older meaning. For example "Za rath ushtra" in persian would be "Zarath" = golden + "ushtra" = camel, but in India, "Za" means "leave", "rath" means "being with", and "Ushtra" means "buffalo". So depending on the presumed origin of the text the translation can change drastically sometimes.
Changes to match Peoples Ideas
When it comes to translating ancient text associated with a particular faith, the bias of the translators needs to be accounted for. Apparently some translations didn't like to have a "Bad God", and chose to interpret the texts differently to exclude that. Some seemed to dislike the occurence of "Dragons" in 11:6b. The word in the Aryan language is "Azim", it appears in many later Persian texts and always means "dragon", but clearly some translations appeared to dislike the magical connotation and excluded it. We've translated the word as "Dinosaurs", considering the literary context.
Religious Agendas
Zoroastrianism features a lot of ideas that have no basis in these texts, but Religions always like to interpret their modern views into ancient texts as proof of the validity of their faith.
For example: the "Gathas" often speak about, "wisdom", "compassion", "authority" and "strength". Modern Zoroastrians believe that God has six archanagles called the Amesha Spentas, the angel of wisdom, the angel of compassion, ...
Obviously such religious agendas lead to some translations drastrically misrepresenting the meaning of these words as angels rather than qualities of a person.
Some translations appear to dislike their myths and stories being contradicted by this book (like the story of Noah, where God destroys the world with water, but in the Persian Zoroastiran version god destroys the world with a long winter and Noah builds a big building for all the animals, instead of an ark). Zoroastrian translations obviously aren't particularly keen on their cultures legends to be contradicted, so they simply alter the translation to fit their preconcieved views. Interestingly this book speaks of this myth as being merely a justificating of a competing religion to justify animal suffering (See 3:8).
An easy way to test for this particular misrepresentation is to look at 3:9 / Yasna 32:9, where "apo" should be translated as "rain". If we look at 11:4 / Yasna 44:4 many of those translations will now happily translate "apo" correctly as "rain", prooving that this isn't merely a case of a preferring a certain translation for "apo".
Other translations clearly come from a more Christian background and choose to not translate "god of kindness" (leaving it as "spenta mainyu") to imply it's somehow related to the Christian "holy spirit" which is seprate from God.
How would we tell that this translation hasn't been altered to fit our modern values and scientific perspective?
This is certainly hard, as lots of religions and religious texts have changed quite a bit over the centuries. For example the Christian Old Testament (or Jewish Torah) have well known alterations that have popped up over time.
The only way we could verify our translation would be if history showed other people of the same faith having the same interpretation as we have, proving our translation to at least be consistent with what they believed.
Luckily there are people in history that had interpretations of this religious text that match our modern translation very closely.
Obviously this doesn't cover all the topics and no translation of an ancient text can claim to be completely accurate to the authors intent, but we've tried our best to do justice to the original and are continually working on improving the translation further.
What if there was another book that contained the same information from a different origin?
That would also help us verify that our translation is correct as it would be very unlikely to make the same mistakes when translating from an entirely different language.
And yet... this is the case!
On some topics the ancient chinese translation of the Dao De Jing is almost word-for-word identical.
As soon as that translation is up to our standards we'll publish it's contents here.