One of the sure signs of someone who is either a new Christian, a cage-stage new Calvinist, or just insufferably arrogant, is the sure and certain knowledge that he or she cannot learn from anyone who disagrees with them. Of course, usually that is on a specific topic - Calvinism (pro- or anti-), Eschatology (whatever position I don't hold), Church Government, Baptism, music, Gifts of the Spirit, the list goes on and on. A typical example would be the Calvinist who says, "John Wesley? He didn't have a clue! I can't learn anything from him!" Or the man who says, "John Stott holds to Conditional Immortality! Heretic! I can't learn anything from him!" I groan wearily, open a volume of Cardinal Newman or B.F. Westcott, and settle down to read something worthwhile. Which is to say, I read books by people I disagree with, and you should too.
One should always do that. Why? Because, contrary to popular belief, people we disagree with can have some pretty good ideas. And some of them write well. It's practically a cliche to say that Newman's English style is brilliant, but that's because it's true. And if Stott is wrong on eschatology (which he is), that doesn't mean he hasn't written some very good commentaries. Open Theist Gregory Boyd has co-written an excellent work dealing with the claims that the Gospels are legendary in nature. The fact that James Denney yielded too much to the higher criticism, and that he was of an Arminian bent, does not lessen the value of his book The Death of Christ. J.I. Packer's involvement in the Evangelicals and Catholics Together disaster does not automatically rob all his writings of value. The fact that R.W. Dale taught Conditional Immortality does not mean that his books are evil and should be burned (sorry).
To take a closer look at this, we can divide books by people we disagree with into two categories, books we actually agree with, and books we don't.
For the first category, it is a fact that many men who we disagree with in one area are extremely helpful in another. Most writers have written in more than one area (though that is less common today than it was in the past). While they may have written some dreadful stuff on one subject, they may have written helpfully on another, Boyd's co-authorship of The Jesus Legend would be a great example. I am amillennial, but I find many of John MacArthur's books helpful - he's not writing on escatology all the time! A.W. Tozer was an Arminian with a mystic bent, but his perception of the way American Evangelicalism was going in his day is excellent. John Wesley wrote a brilliant treatise on Original Sin against John Taylor of Norwich. To reject all the good someone has written because of the bad stuff they have also written is a case of cutting off your nose to spite your face!
As for the second category, books you disagree with, reading these is optional, though mature believers will be helped by reading things they disagree with. It is a challenge. Read the best of the Arminians, and ask, why is this person wrong? (the answer is poor hermeneutics and an inherited tradition, by the way). And you will find that heretics can be very nice people at times. Sometimes they're nicer than the orthodox. Sometimes they're not, William Robertson Smith and William Hale White come across as quite insufferable! But Basil Martin, Leslie Weatherhead and W.E. Orchard are nice people.
This procedure helps you to think for yourself. The danger of only reading people you agree with (or worse, only people your pastor agrees with) is that, as you never get out of your comfort zone, you create a sort of mental cocoon around yourself, and the thinking processes harden. But when you read Newman, you have to ask why you disagree with him. You enter into a critical dialogue, a debate, with the author, and you have to think. And the great thing with a book is that you can actually put it down and do the thinking!
And finally, read biographies of people you disagree with. That can be most challenging of all at times, seeing those who did what was right while they thought what was wrong. Or did what was wrong when they thought what was right! And why was it people embraced false ideas? The answer is always more complex than "He was a secret Jesuit" or "He was just evil." Now, the answer is always "he was wrong," but the great question is, why was he wrong? And that is what the biography will help you with - even if the real answer isn't the one the biographer gives. Oh, and autobiographies are often more fun where this is concerned - and the more indiscreet and chatty the autobiography, the better. Basil Martin's An Impossible Parson is a good example. Newman's Apologia is more formal (but then Newman is always formal), but just as good in its own way. Most people, however, will prefer Martin's humour. And finally, the young minister should read ministerial autobiographies in order to give thanks that the quality of food in theological colleges has improved in the last century!
Oh, and this does apply to Fundamentalists as well, though I have generally found that liberals write better autobiographies. Now, I have a biography of Robert Newton Flew to read...