The perceived importance of religion (or religiosity) declines predictably with development (however measured), allowing one to predict how long it will take for religion to become unimportant for the majority of the global population. It will take approximately a quarter-century.
Uruguay is as secular as Switzerland or Germany, and it just legalized abortion. Given that poorer countries are generally more religious, one would expect Uruguay to be more devout than Germany. Why is religion so weak there?
Is the loss of religious belief something fear? Contrary to the claims of religious leaders, Godless countries are highly moral nations with an unusual level of social trust, economic equality, low crime and a high level of civic engagement.
If we assume that prosperity is responsible for declining religiosity in the world, and that prosperity will continue to increase, it is possible to estimate the date at which the world will switch over from being a majority believing in God to majority atheist.
We are witnessing the emergence of an unstated yet court-sanctioned right, one that makes no appearance in the Constitution and yet seems to trump the First Amendment at every turn: the right to not be offended.
No matter what age the kids are or what the situation, telling them you no longer believe can be tricky. Help them to understand your changes as a matter of spiritual growth rather than spiritual abandonment.