Will the US Consitution ever be "out-dated" ?
Will the Geneva Convention rules ever be "out-dated" ?
Will the Bill of Rights ever be "Out-dated" ?
Will the Magna Carte ever be "out-dated" ?
The Bible doesnt change its mind of topics, its a work of written perfection which is a constant truth. IF you think it needs modernizing, all you are doing is noticing the gap between what it says is right, and how far wrong society has gone.
The idea is that each of the documents above, plus the Bible are timeless. They are supposed to be true in any time frame. They wont always be popular, they wont always be adhered to, but that is because society changes, not the words of the documents
I hope that helps explain