If further books were added to the Bible, that would equate to saying that the Bible we have today is incomplete—that it does not tell us everything we need to know.
Kung may iba pang aklat ang dapat madagdag sa Bibliya, ito ay katumbas sa paniniwala na ang Bibliya na meron tayo ngayon ay hindi kumpleto - at hindi nito itinuturo sa atin ang lahat ng dapat nating malaman.