Hello again Peter!  You may call me by my screen name, which is actually spelled without the "i" in "knight" - knght4yshua; or by my first name, which is much simpler - Adam. 

You started at the end of your post to dip into a little more of where my mind seems to want an answer.  Again, although I agree that apostolicity, orthodoxy, etc…are all good tools to some degree, these have shown to be flawed as well.  If you have done any study on textual criticism, which I am assuming based on your responses thus far you have, you know that there are numerous manuscripts that were not included in today’s canon.  Why? 

Some "gospels" were accepted and TAUGHT as the Word of God in certain 1st & 2nd century assemblies, while others condemned the exact same book as being heretical.  Is there some medium through which these two groups could come that would show them that that particular gospel was, or was not, the Word of God?  I know that the first answer rising up in you is probably - "Yes!  The Holy Spirit!"  And again, where I agree with you to some degree, we both have to agree that being "led by the Spirit" is a phrase that is tossed around far too much today.  Some believe baptism can be a simple sprinkling on the head, others believe only in full emersion.  Some believe in the continued use of the gift of speaking in tongues, others say it is of the devil.  Some say Yahushua is God almighty, others say he is not.  Yet seemingly ALL of them claim to be "led by the spirit".

So, if possible, what else is out there, that we can all access, that could solve the problem that the two example assemblies above were having?  How can we determine if that "gospel" is the Word of God, WITHOUT getting into a "Well, I feel like the Spirit says it is…." type of argument?  Do you feel that there are standards out there against which we can measure any writing to determine whether or not it is inspired of God?  If so, what do you believe these standards to be?