I wrote a little series about this topic a couple of months back, and this week I found a rather famous voice agreeing with mine. It's found in R. C. Sproul's commentary on the book of 2 Peter, and it reads like this:
One of the great concerns that Martyn Lloyd-Jones expressed in his lifetime was the way in which the twentieth-century church removed itself from knowledge of the Old Testament and how very few preachers were preaching from it. I am baffled about why there is so little Old Testament preaching. When I was first preaching, I kept a file of my sermons, and after about a year's worth of preaching, I went through that file and discovered that about 75 per cent of my sermons were from the Old Testament. I see the Old Testament--that thick volume that makes up the majority of the Bible--as the autobiography of God Himself. We need to understand more than anything else who God is, and we are shown that marvelously in the pages of the Old Testament.
If you want to go back and see what I had to say about the importance of our knowing and understanding the Old Testament, click on the links below. I promise you, it's worth a look.