You can't say that God is weak for not preventing man from hiding His words. As God said He does whatever He wills.
You are saying that God's word is established in Heaven forever, which I agree with. However, He didn't prevented man kind from hiding the true message. You can argue here again why He didn't prevented man kind? Well I will say it again, God does what He wills, He will not be questioned, but we will be questioned.
We can't say that man has power to corrupt the words of God, but the true message of God can be hidden by man by the permission of God as God said in the verse below.
[5.15] People of the Book! Our Messenger (Muhammad) has come to clarify to you much of what you have hidden of the Book, and to forgive you much. A light has come to you from Allah and a Clear Book, God has send a final messenger to inform the community that the true message has been concealed from them by those who wish to gain pleasures of this world. Well we can think of it as this was the part of the God plans. God knew that His message would be concealed, but man kind forgot who is the best of the Planner. When the time came to complete His Favours on man kind God send the final messenger with a book which He promised to protect till the end time. If God didn't protect this book "Quran" until the end time, how would we know what's the true message and what's not?
Do you think it would be right for God to send us to hell by allowing man kind to also hide his final confirmation which is "Quran"?
Lastly, you shouldn't have these doubts that how can man have power to corrupt the words of God, these doubts are from the devil. You have to remember one thing, we only exist today, its because the Wills of God.
And as said by someone " The pen has been lifted and the pages have dried", everything has been pre-ordained just like a completed script, and now the actors have started performing the scenes.
Edited by Mercyonmankind, 04 December 2011 - 05:20 AM.