Q&A: The Q document — does it matter if Gospel writers used written sources?

Q (Quelle, German for "source") is a hypothetical document proposed to explain material common to Matthew and Luke but absent from Mark. No copy exists. Mike's position: it does not matter whether Gospel writers used written sources, oral sources, or both, as long as the writing was Spirit-led and historically careful. The source question does not threaten inerrancy.