I don't know how we can solve this problem, but until we do, we'll only see an acceleration of the current trend where the good, smart, examined-life people leave, which of course just makes the problem worse.
Unitarian-Universialism seems to be a refuge for people like you describe. Or at least, that's my perception from the outside. I actually haven't meet that many people who actually belong to that group.
Lots of people have been considering these questions for millennia. The institutional religions and their scriptures and traditions represent the condensed wisdom of a lot of people, and it's sort of silly to throw all that out the window just because you disagree with some of their conclusions.
Anyway, your initial claim is incorrect. You have increasing difficulty etc, etc, but there are a lot of smart, examined-life people out there that remain churched, or who leave their church but continue to believe in God. (Or gods.) If you can generalise anything, I think it's that smart people have a hard time with corrupt individuals and institutions, but that's not a particularly interesting or novel assertion.
If you can generalise anything, I think it's that smart people have a hard time with corrupt individuals and institutions, but that's not a particularly interesting or novel assertion.
Indeed.
Something slightly more interesting is that the church (whichever one is local to you) has a lot less direct power over your life than it used to (like 300 years ago).
And switching religions isn't the shooting offense it used to be either.
Another interesting bit is that with increased communication technology, it is easier for aforementioned smart people to learn more about their church in much greater detail and scope.
Is someone aware of a good book which discusses these sorts of issues from a historical perspective?
Speaking as a Unitarian-Universalist (by birth, upbringing, and choice), I can say that it is true that many UU folks migrated from other religions. Their reasons, however, only occasionally have to do with the issues of authority, the source of truth, the contradictions in various scripture, etc. It is much more common for people to come to UU after having deliberately and vehemently discarded all organized religious institutions in reaction to an oppressive religious upbringing. They tend to be walking wounded, and the very mention of certain trigger words such as God and Christ or even amen or prayer will make them uncomfortable and upset. These are not people who have considered religion and decided they like one faith better than another, these are people who are seeking a church-like community that will not remind them of the unpleasant aspects of their childhood.
Such people make up roughly half the congregation I grew up in; the other half are mostly the examined-life types, which is largely made up of people who are born and bred UU. Not counting those under 18, who we can expect to be still figuring out what they believe, there are only a very few who are there more by habit than by decision. I will also mention that UU congregations are often very different from one another, so this mix is likely unique to my home congregation and should not be considered valid across the entire UU world.
I had a friend in high school who became a born-again fundamentalist Christian while I knew her. She had not been brought up that way, but had chosen fundamentalism after careful consideration and examination. I cannot fault her for that, regardless of what I might think of her chosen faith (or, more to the point, the vocal majority of people who have chosen that faith). I had several interesting and informative discussions with her, and it was clear that she had come to her chosen faith with her eyes open. By the same token, I cannot respect someone whose faith comes from one parent or the other without conscious consideration, regardless of how enlightened I might consider said faith. (Note that being of one's parent's faith does not necessarily mean that one did not consciously choose it, but that is most often the case.)