Many don't listen to what they read in the Bible, they read only to memorize it. Therefore, they have to open a Bible to quote ALL THE TIME something they want to speak to others. They cannot digest the Word of God to become their own words, they cannot become effective witnesses.
The Bible also has great many golden phrases in various languages. These are also good to put them to heart in meditation as well as growth not just in literature or eloquence, but in enjoying God.