(Pro 22:20 KJV) Have not I written to thee excellent things in counsels and knowledge,
Part of the heritage Christians received from the Jews is a religion that demands literacy. We have seen how this worked out in history. The original Sunday School classes were established to teach poor children to read. The early settlers in America established schools and colleges so that their children could read and go on to read great things. The Bible is full of references like this that talk about writing things down and reading things.
Oral tradition is nice. Testimony can be uplifting. Experience teaches. Over it all is the written word God has given us, the Bible.
So? Use the resources we have. There is no excuse for ignorance in a literary society and since God wants all to come to salvation, read and teach to read.