Fitting the glove to the hand, or the hand to the glove

Do religious texts reflect the world, or shape it? How much does writing make the morals so.The bible has created scores of rules and taboos that, before its creation, society lived without. For example, the condemnation of homosexuality. Homosexuals had been socially acceptable in many of the countries that, after Christianity, condemned it- such as Rome. Was this a product of public needs and sentiments, or was it the sentiments of the small group of bible writers who then riled the rest of the people? How many of our "intrinsic moral instincts" would exist without religious systems guiding our thought?
I grew up without the immediate presence of any religious text, but have recently had the privilege of discussing my world views with a devout Christian woman. The conversation showed me how essentially a religious text can change the way you see the world. It changes the way you develop ideas about what's "normal" or "acceptable", and with or without a book, it can be very difficult to make judgement calls. My friend sees the world through a lens that deeply includes the contents of the bible, but it is very hard to come to terms with the fact that, sometimes, she disagrees with it. I see her going through an internal struggle, trying to both follow the contents of his bible and remain true to herself. Unlike my friend, I have no book laying my guidelines before me. This can make it difficult to be confident in my moral choices, however, it saves me the tribulation of trying to bring my own beliefs to terms with a book that I'm supposed to follow faithfully. I wonder how many people in the world twist and reshape their own beliefs to fit their faith, repressing ideals or resisting acceptance because the writers of the bible, two thousand years ago, tell them that something is wrong.