Don't change the discussion. Of course, Scripture is God's Word and It accomplishes His purpose. We're talking about Sola Scriptura here... the doctrine that gives all authority to Scripture alone. Show me in Scripture where Jesus commanded his followers to write the New Testament so the future Church (some 300 years later) would be able to have something to follow...
I can show you where they said themselves that they didn't bring the written Word with them but rather the living Word of their testimony and instruction in Tradition (2 Thess 2:15, 2 Tim 2:2, Rom 10:17, 1 Pet 1:25, 1 Cor 11:2, Acts 2:42, Acts 20:35, John 21:25). That is the authority given the Church and it is from this authority that the New Testament was written.
This isn't a "chicken and the egg" scenario... if having the New Testament is the requirement for the Church then there was no Church until the Gospels and Epistles were written and compiled (beginning 30 years after Christ's ascension and ending 300 years later with the Canon of Scripture). Rather, an honest view of history shows that Christ gave us His Church (Matt 16:18) and His Church gave us the New Testament.
I didn't believe I was changing the discussion. I was asking a question that logically followed from you claiming the apostles were not "assigned" to write books of the bible. If you agree that scripture is "God breathed", then obviously they were "assigned" to do it.
Good grief.