If we took a look at the people, we could see taht many of them don't believe in any god... We can rarely see true chretians, but the people continue to follow the eldest traditions of their country's religion, only in order to have holidays...
The religions like christianism, hindouism, islamism and judaism will stay many years because they are most prevalent in their regions of world...
(Pardon pour les fautes :/ J'ai que 15 ans / Sorry, I can make many errors because am 15 years old)