I am a bog standard British bod. UK is a Christian country - with a culture based on Christian teachings (whether or not any 'god' is involved...). I am broadly libertarian - if you disagree, then you have a different definition of libertarian to me, and I don't really care! I came across some stuff on Jesus, Christianity and Libertarianism, and started doing my own rooting. I haven't got far, but got this far so far.
I am not arguing a religious case either way, just following a logical case to a logical conclusion from the story of Jesus as per the bible.
According to the bible:
Jesus, himself, sent out 12 disciples to spread his word, our knowledge of how they did this is made up from, and by, the four biblical gospels (Matthew, Mark Luke and John).
Jesus, himself, evidently considered the spreading of his word in this way, was all that the rest of mankind required.
Jesus would have known that, at the time, most people hearing a gospel would only hear one gospel, and it might be any one of them.
From this we must deduce that he believed each of the gospels is adequate in and of itself - anyone of them would do - because that is all that anyone at the time was likely to hear.
We know their lessons are not literal, that they are 'parables' stories meant to convey a message - a message that will be understood by those who they are meant for. Jesus said that an individual will be saved only through him, not through anyone else. So nothing can be valid unless you understand it for yourself, no one else can can save you, the message is accessible to every individual, if you don't understand it or 'get it' yourself then it is not part of the message intended for you - how could it be otherwise?
Old testament? And the rest of 'the bible'? Of academic interest maybe - but not something that Jesus asked to be spread, so clearly not needed for the spreading of his message.
So the first thing seems to be only the four gospels matter - any one of them is all you need...
Here endeth the lesson so far...