I'm of the assumption that there is no middle ground between the two. If you have an argument to refute this basic assumption, please feel free to do so.
Night Owl said that words alone are insufficient to prove a fact. This is absurdity to the extreme. Most people do not doubt the existence of the Roman Empire, the proof of which is solely based on words. The fact of Jesus' immaculate conception has been independently verified by various sources. The fact that they were compiled into the Bible does not negate their value.
Historical writings of Jesus' immaculate conception don't exist outside of religious writings, because those that were witness to God's work became his servants and preached the truth of Jesus Christ.