There is no way this will happen. Religion works in the favor of governments. It keeps some people in line and keeps the minds of people busy. Plus in some countries they can actually control religion which is yet another way to control people.
Religions will slowly erode into the past, and will more than likely be replaced by other religions. In fact this is already happening. Even as the world trends towards atheism, more people start following other cults and belief systems, such as the political cults we see today. Even without traditional religion people will continue to feel the need to align around beliefs and causes, so you can expect this not to go away.