Look at it this way. We know that the world was destroyed, but somehow some people survived. I figure that yes, old religions probably did endure, but after like....I dunno 10,000 years or so, however long it's been since the earth's rebirth, things will have changed. There is no Islam, for example, but there may be a religion with similar ideals that developed from Islam.
Get my drift?
Just how I personally see it.
