Once Jesus comes back to save the Earth, as it says in the Bible. "Blessed are the meek, for they will inherit the Earth." The word 'inherit' does not just mean 'possess' but to be given something by someone after they die. I don't think that it meant that after Christ died the meek will be given the Earth, or that they had a right to the Earth once they were born because they were meek. After and before Christ, according to some histories, died, the meek were usually slaves and servants, and therefore had no control over the Earth. So, perhaps the meek will get the Earth once Jesus comes back.
Personally though I think the Bible only says that as a way to manipulate common people to be passive and submit to authority in hope of becoming powerful and free in the future (in Heaven).
My theory: the meek will never inherit the Earth, and only the strong survive and prosper.