I had read R.C. Sproul's The Holiness of God while in college in the late 1980s, and recently finished a re-read.
Even when Sproul first wrote the book, he recognized that many people left the church because they found it boring. Yet the church that contemplates the holiness of God will be anything but boring.
I still have the same copy that I read 20 years ago, and it was interesting to see what I had marked the first time. This time around, one thing that stuck with me was Sproul's observation that while we talk a lot of God's grace, his love, his mercy, the Bible nowhere says "God is grace, grace, grace, or love, love, love, or mercy, mercy, mercy. It does say, however, that God is holy, holy, holy."
If you've previously read The Holiness of God, get it out and re-read it. If you never have, get one.