If popular means "most practiced" then it is Christianity.
If popular means "fastest growing" then it is Islam ( however this is mainly from birthrates and not converts).
If popular means "most converts" then it is Buddhism or Hinduism.
If popular means "least disliked" then it is Buddhism and Taoism (Daoism).
If popular means "most talked about" then it is Atheism and Christianity.
What is the strangest Religion ever ??
No, it is the worlds third largest religion, it has about 950 million followers which is about 14% of the world.
Too popular
The worlds greatest religion is Christianity. It is the largest religion and one of the most peaceful.
George Wilkinson Morehouse has written: 'The wilderness of worlds' -- subject(s): Popular works, Religion and science, Evolution, Cosmology
Judaism.
I believe it is Judaism.
islam
Christianity has about 2.2 billion adherents, about 31% of the world population. Islam has about 1.8 billion adherents, about 25% of the world population. It is predicted that Muslims will outnumber Christians by 2070.
Christianity
The worlds largest religion is Christianity and the second is Islam
Beleive it or not there is a releigion born every minute. It depends on what YOU believe in to choose you religion.