religion and atheism have good and bad points if it were adopted by everyone,
a completely atheistic society might be less likely to spend time and money on charity and 'doing good things' (not by all that much), while a completely religious society will be less likely to study anything against their religion (seen it plenty of times in the past).
on the whole society would be better if it were to stop believing in their gods (over time- not over night), we'd have less wars, more intelligent leaders, and quicker advancement of technology.
With or without religion, you would have good people doing good things and evil people doing evil things. But for good people to do evil things, that takes religion. - Steven Weinberg