Is Christianity slowly diminishing and what worldviews are becoming more popular?

Answer 1

AnswerChristianity is slowly diminishing in the West, partly offset by conversions to Christianity in developing countries.

In some Western countries, Islam is growing rapidly, although this is more the result of migration than conversion. Numerically, the most rapidly growing worldview is Atheism. Buddhism and alternative religions such as Wicca and neo-paganism are growing quite rapidly.