What causes such an attitude in people? There are probably a lot of reasons, but there is one in particular that tends to stick out rather prominently in my own observations (which I realize does not prove anything in and of itself). Many times the "hero theologian" is one who had a profound impact on the thought life of the individual. It could be that the person's hero led them to faith in Christ, or more specifically in my circles, led them to the Reformed faith. While not knowing the individuals personally, I know of a particular church where members left because the pastor taught a Sunday School class refuting a book written by a well known
It's not just guys like Harold Camping though. I see this happen to folks (on Facebook and online discussion groups) who have what we might say are the more conservative theological/pastoral heroes, i.e., men who are regarded as having a high view of Scripture: names like John Piper, John MacArthur, RC Sproul, J Gresham Machen (really, OPC guys can go too far here also!), Meredith Kline, Tim Keller, John Calvin, Doug Wilson, RJ Rushdoony, Michael Horton, Cornelius Van Til, and Joel Osteen. Okay, that last one was just to see who was really paying attention; that name doesn't belong. In all seriousness, while it is a good thing to remember those who went before us and honor those who are currently seeking to proclaim with boldness the truths of Scripture, we cannot make these or any men idols regardless of how much God may have used any or some of them in your Christian walk. They are (were) fallible. They make (made) mistakes. They sin(ned). They need(ed) God's grace in their sanctification. Do not merely assume that simply because "great theologian so and so" said it, that his comments settle the matter. Perhaps he's right, but do not be so quick to assume it merely because it was he who said it - the word of God is what settles the matter!
How do you know if you have made a theologian/pastor into an idol of this kind? Give yourself a little test: do you ever quote other theologians/pastors/authors? Do you ever recommend other theologians/pastors/authors to friends or just your favorite one? Have you ever found anything from your favorite theologian with which you disagree and can articulate what you dislike about it? When someone else critiques your favorite guy in a way you had never considered, do you simply dismiss it with a wave of the hand or do you really think about the substance of the critique? Remember that it is God who saved you; it is God who sanctifies you. These men are merely the instrument by which God brought you to Himself. I'm not saying you should give away all your books from your favorite author, but rather to have a proper perspective. A simple way to do this is to expand your list of theologians whom you read. What do others say about the matter? What do others who disagree with "my guy" say about the matter? Of course, the Holy Spirit speaking in and through the word must be the final arbiter in all matters of doctrinal controversy. We ought to thank God that He has raised up men, both past and present, who can expound God's word in great and meaningful ways; let's not make more of them than they are or would even wish to be. They are men saved by grace through faith, men who need the same grace you and I need.