The Harris research data has shown that religion is declining in almost every generation in every country (an interesting exception is France where 38% of those over 55 believe in God, but every other generation has between 22 and 26% believing – however, the younger generations increase the proportion of atheists to agnostics!) In the US, 64% of 16 to 24 believe in a god, with 18% agnostic and 8% atheist, and then each older generation increases in religiosity, with 55+ showing 78% believing in God. Britain is fairly typical of the European pattern, with 40% of those 45 and over believing in God, but with each younger generation reporting lower levels of belief, with just 23% of 16 to 24 year olds believing in any form of Supreme Being.
Overall, the US looks a lot like Western Europe 30 or 40 years ago. At that time most Europeans still believed in a god, but younger generations were more atheist and agnostic than their elders. That trend has continued with religion steadily declining, generation by generation.
While a current snap shot of religious belief makes the two continents look very different, the long-term trend appears remarkably similar. Young people are growing up less religious and the most religious generations are dying out. At the same time, support for secular government and greater tolerance is rising with each new generation. Or to put it another way: the future looks bright for humanism.