Some people would say that the Bible is a sacred book and they would never dream of using highlighters or pens in their Bible. While I agree that the Bible is a sacred book, I believe the content is more important than the paper it's written on!
The She Loves God Conference this year had Joshua 1:8 as its theme:
Study this Book of Instruction continually. Meditate on it day and night so you will be sure to obey everything written in it. Only then will you prosper and succeed in all you do.
Highlighters are my helpers with studying and meditating on God's Word. What's yours?