I don't believe that "religion" per se has introduced anything new to human thought and morality and "spirituality". I believe that religions are a product of what humans collectively knew and sensed and felt at the time that a particular religion was born. I think that religions reflect "our capacity at the time". Religions didn't give us those "capacities", they only institutionalized them and made them more concrete. If you look at different human societies around the world, you will see that they have varied opinions about different issues. What is concidered immoral in one society, is cosidered perfectly ok in another. What religion does, is to make a society's moral values and codes "official", and force a settlement in any disagreements and debates about these matters, so that the society can be more cohesive and unified.
People like Bahaollah, Jesus, Budha, Zartosht, were visinaries and geniuses. Some people are geniuses in mathematics, some in music, and I believe that some are geniuses in the "art of humanity". People like Mozart are able to compose music since the age of 3, and compose profound music by their teenage years. Somehow they can just visualize music in their heads, and bring it out of their heads with little effort.
The Indian mathematical genius Srinvisa Ramanujan was able to come up with mathematical formulas and proofs out of thin air. He was somehow able to visualize mathematical facts in his mind and express them without much effort. He didn't have any formal education and training in mathematics either. His brain was just somehow inately able to do those computations.
I believe that a person like Bahaollah was also a genius. I don't believe that he was somehow devinely inspired; well, mainly because I don't believe in any such thing. I believe that Bahaollah, like Ramanujan, was able to inately and instinctively visualize and produce facts, principles, guidelines pertaining to the "art of humanity". He was a natural "musician" and artist. He was a Mozart of "spirituality". He was a Ramanujan of morality.
Ofcourse I cannot prove this, because Bahaollah is no longer living, but this is my theory, and I guess without any evidence, or ability to test and verify, it is as good a theory as a "devine inspiration".
Back to the topic of morality and where it comes from. I believe that a judgement about the "goodness" or "badness" of a behaivior like incest is something that comes from whithin our animal instict. Somehow in our biology, we "know" that incest is an evilutionarily disadvantagous behaivior, as the offspring of such a mating would be mentaliy and perhaps physically and sexually handicapped. This instinct keeps most people from incestual relations. When this "rule" is broken, it can have disasterous consecuences for the community. For example, it is thought that during the reign of the Egyptian king Tutankhamun, incest was rampant in the royal court, and that is what may have led to the demise of the 20th Dynasty.
This is where religions come in, and they enforce the formerly unwritten rule, and sort of "set it in stone".
Religion is a tool for ensuring the survival of human societies. It is a primitive form of government and law. It is brought into being by a "founding father" (the analogy to the American revolutionaries is intentional), who is a visionary, a genius, and feels that there is gap that he needs to fill. After the founder of the religion dies, the tradition falls into the hands of a ruling elite (clergy), which amend it and embelish it as they see fit (mainly to add to their own influence and power). When a religion becomes a tool of religious apertheid, it means that it has reached the final phases of its evolution, and it is nearing its demise. That's what happened to Zoroastrianism (allegedly), and Christianity, and will soon happen to islam.
Science does not have the responsibility to provide a moral guideline for humanity. Science is only a way of answering questions about the makeup of the world. Science can help us understand how human societies evolve, and how moral codes are established (anthropology), but it does not take on the responsibility of actually doing the job.
Where our sense of morality and ethics come from, are from whithin us, and from the collective interactions of all humans. It comes from our emotions and feelings, and from our knowledge about them. Without knowledge, there is no feeling. Emotions alone cannot be a guide for behavior and actions and decision. One must be able to Feel emotions, and KNOW that those feelings and their underlieing emotions belong to his or her own individual being. That knowledge and ability to feel emotions, and attribute them to a being called "I", comes from within our brains. Varying degrees of damage to the brain, can selectively destroy various layers of a person's consciousness, from extended and high level consciousness, down to core consciousness and basic emotions.
I agree that having "darse akhlagh" (lessons of morality) for kids is a very good thing, and better even to have it in a group and communal setting, since we are communal beings, and after all what good is akhlagh if it is without a community. Such "darse akhlagh" however, does not have to be dependent on unfounded and baseless theories of "god" and "prophets" and "angels" and "soul" and "rooh". If one dispels with all these unfounded beings, the "akhlagh" does not go away with it. Morality does not depend on religion. Morality comes from whithin us, and from our communal interactions. It comes from knowledge and feeling that we are all equal (equally tiny particles of dust in the universe), and therefore must live our lives in mutual respect, because none of us are any more significant in the universe than another, so we might as well help each other live our short lives in full enjoyment together.