Quote from tradingjournals:
Is there a scientific study that supports that conclusion (the guy in the vid seems to be mainly a propagandist, and therefore not to be trusted)? Is not Christianity the dominant religion in the world with Islam second? What is the second fastest growing religion if Islam is the first?
Yes, according to the World Christian Database, Islam is the fastest growing religion in the world over the period of 2000-2005:
http://en.wikipedia.org/wiki/Claims_to_be_the_fastest-growing_religion
In terms of the current breakdown of numbers:
1) Christianity 2.1 billion
2) Islam 1.5 billion
http://www.adherents.com/Religions_By_Adherents.html
Obviously then, the world already has more Muslims than Catholics:
http://www.catholic.org/international/international_story.php?id=27384
Here is a good map illustrating the distribution of Christianity vs Islam over the world:
http://en.wikipedia.org/wiki/File:Christ_Islam.png
Interestingly, there are 4 million Muslims in Germany (4% of population) but only 2.5 million Muslims in the whole of Lebanon (60% of population). There are also nearly 2.5 million Muslims in the US (0.8% of population)
http://en.wikipedia.org/wiki/Islam_by_country
By 2050, there is a good chance that Islam will be the world's most dominant religion primarily due to higher birth rates.