Religion's "half-life of one generation"

Here is a report of a provocative (and dubious) new study suggesting that belief in God among the British is falling at an even faster rate than church attendance and will shortly be near extinction:

Organised religion is in near-terminal decline in Britain because parents have only a 50-50 chance of passing on belief to their offspring, a study claimed yesterday.  By contrast, parents without faith are successful in producing a new generation of non-believers, it said.

The report identified institutional religion as having a "half-life" of one generation, as children are only half as likely as their parents to say that it is important in their lives.

If the same mode of analysis was utilized during New Testament times, of course, conventional wisdom would have had Christianity and its rag-tag band of followers dying out long ago.  Has evangelism become such a relic that it need not even be considered as a factor in predicting the future course of faith?

(HT: Touchstone)

Rob