Todd, I would ask in response to this which version of the dozen of versions available? Beyond that how do you apply a 6 year old text to modern conceptions like abortion, space travel and other ideas that didn't exist 6ooo years ago?
King James, NIV, etc. It doesn't totally matter to me. Even though the wording/language is different, the general subject is the same. Yes, there might be some wording that can be interpreted one way or another, but the message of Jesus dieing for our sins is the same as far as the scriptures that I have read.
As far as how a 6000 (although a lot of it is around 2000 years old) year old text applies to modern conceptions, I'm not totally sure. It's probably more personal conviction for me. Example: Religion aside, I don't think abortion is right. Religiously, I'm not totally sure. It does mention some things that could help you argue against abortion, but it's not totally concrete since they didn't have such a thing back then.
Who sets these standards and back to the op why don't we all know what these standards are?
Depends on the religion. In my beliefs, it's the Bible, and the Holy Spirt's work in my life. Obviously, a Jewish Rabbi might have a different standard by using the Torah and so on. The only way you'd know and understand the standards is by reading the book.
the sources after this put the book of Matthew written between 60-85 AD. JC is reputed to have died in 30 AD so actually is the author, believed to be Matthew's opinion on what Jesus may have said if he had been around him or very likely was not.
http://en.wikipedia.org/wiki/Gospel_of_Matthew
http://www.allaboutjesuschrist.org/when-was-the-book-of-matthew-written-faq.htm
http://www.wacklepedia.com/g/go/gospel_of_matthew_1.html
Relating this post back to the OP isn't it odd that Jesus came to make a book that would be seen by his followers at the greatest in history but forgot to write any of it himself? Does that seem like overt and open to you?
No, I don't think it was odd that Jesus didn't write a book physically. His ministry lasted only around 3 years (time between when he was baptised by John and when he was crucified). I think he had plenty of issues on his hands during these three years. He was pretty busy healing people, walking the desert for 40 days, raising people from the dead, etc. The reason he had the 12 apostles was for them to ultimately spread the word. The first 4 books of the new testament lined up pretty closely, even though they had different authors, and it was definitely possible that some of the disciples were still alive 30 to 50 years later.