@ Hypognosis
Chicken and egg is a fair point. Many religions adopted rules, perhaps mostly taboos, to address contemporary issues and that creates the problem of credibility when measured against criteria such as eternal truths, if beliefs include what might be dismissed as (now) obsolete "fixes".
There is also the traditional criticism of religion for anthropocentric obsession, especially in view of today's cosmological awareness. This applies not only to worshippers of sun-gods but to pre-Galilean Christianity.
On the same point of sujectivity, Judeo-Christian tradition has the difficult notion of a chosen race at its core. It was therefore understandable that Christ would adopt the prevailing Judaic culture of the society into which he (or "He", if you prefer) was born.
... But not without question or challenge, of course. There is the paradox that the Judaic leaders regarded him as a revisionist subversive: but in many ways he was a reactionary, frequently rebuking them for deviating from traditions and above all for hypocrisy.