The non-Christian thinks that his thinking process is normal. He thinks that his mind is the final court of appeal in all matters of knowledge. He takes himself to be the reference point for all interpretation of the facts. That is, he has epistemologically become a law unto himself: autonomous.
Dr. Greg L Bahnsen, Always Ready, p. 46
What is sad is that the quote above could be said just as easily about evangelicals. When push comes to shove, most set themselves up as the final authorities of what is to be believed and rejected. They are all experts. They all know what is best. Even when what they think and know to be best, is in complete contradiction to what Scripture says.
The issue is and always will be: who is our final authority? What is our final authority? It must be, as always, God’s word. This means that when we come to God’s word that contradicts what we have commonly held to be true, we must reject what is commonly held to be true, and accept it as God’s word.
Otherwise, we are no better than the non-Christians that Dr. Bahnsen writes about in the above quote.