John Piper says,
I [do not] want to give the impression that I think there is virtue in reading many books. In fact one of my greatest complaints in seminary was that professors trained students in bad habits of superficial reading because they assigned too many books. I agree with Spurgeon: “A student will find that his mental constitution is more affected by one book thoroughly mastered than by twenty books which he has merely skimmed, lapping at them.” God save us from the allurement of “keeping up with Pastor Jones” by superficial skimming. Forget about “keeping up.” It only feeds pride and breeds spiritual barrenness. Instead devote yourself to boring in and going deep. There is so much soul-refreshing, heart-deepening, mind-enlarging truth to be had from great books!
I actually think that for some people this point is not true. I know a few people who can devour a lot of material quickly and then process and retain what they read effectively. In fact I am married to one such person. But for me, Piper's quote rings true and is an encouragement. I read pretty slowly and I don't seem to be able to make a lot of time for reading in any case. So to choose a few really good books and read them slowly and carefully works for me.
From John Piper's Brothers, We are Not Professionals
HT: Desiring God blog