How in turn will they hear without someone to preach?
JW Facts already answered this, ( At Luke 19:40 Jesus said “I tell you that if these should keep silent, the stones would immediately cry out.”) but you might just get into Bible ping pong, which then makes an objective person like myself realize that perhaps the Bible is not the great book that is easily understood after all. And just because people are exposed to the Bible, doesn't mean they'll turn around and believe in it.