I think this is the case, as well. As time changes I think that cultural and religious differences will lessen more and more, things will become more and more global and God will no longer need to show himself to the masses in multiple different ways, not saying there will only be one type of religion but I think religion in general will become more unified. Society will become more unified.
I think that becoming a global conscience is important to a planet that reaches the space-travel era, if in fact the universe is full of other life-forms Earth will need to adapt and unify in order to survive, but again that is a whole different topic isn't it?
At the time becoming a one-culture one-religion global conscience also has some very scary implications... I'm not sure how I feel about it. All I know is that throughout time their has also been two constants up to this point:
1) The world is always changing
2) There are always skeptics who fear and hate that change and believe it will bring "the end of the world"