Science deals with the tangible world, observing and analyzing the physical aspects of life. Religion defines the spiritual dimensions that assign value to, and provide guidance towards happier and more efficient functioning within, the physical realm. Both use various models to explain abstract ideas.
However, even though all models are imperfect, some can be useful--especially when trying to understand the interaction between the physical and the metaphysical. Similes, analogies, parables, fables and storytelling have all proved helpful when understood in the general sense, but problematic when accepted as literal.
In both science and religion, old models for which the original context and symbolism have been forgotten can become rigid and much less useful in trying to make sense of life. For instance, early medicine used analogies to the familiar properties of air, water, fire, and earth to explain health and disease, even though we now know the human body isn't that simplistic. Nor does spiritual transformation require literal baptism by fire, wind and water--but believers' knowledge of their effects makes it easier to understand the difficulties of developing good character.
The Bahá'í Faith teaches that humanity has been evolving steadily, but was always possessed of 'human' potential irrespective of what the species looked like at any point in its development. The seed contains within it all that it needs to become an oak tree, and was always a 'tree,' even when it looked like an acorn, for example.
Starting about two million years ago, ancestral human brains began growing rapidly, eventually tripling in size. This led to the creation of a thinking, problem-solving, tool-using, linguistic brain. This thinking brain expanded beyond and above the physical brain, which deals sensation and movement, and the emotional brain, that controls feelings and mood. This conscious, thinking brain is the source of language.
Suddenly, geologically speaking, individual human brains had access to what other brains had seen, learned, remembered over time and generations, and multiple perspectives to aid in problem solving. Collaborative activities such as hunting, foraging, raising children and sharing knowledge may have held priority in early survival communication, but being part of a verbal tribe resulted in a phenomenal explosion of social development.
In a mere two million years, the human species expanded successfully into every climate on earth. Language drove this evolutionary explosion, but only because humans had already learned how to love and how to belong to one another, without which cooperation is not sustainable. That unity has always been the purpose of core religion. Granted, cheating, stealing, lying and plotting to kill each other developed, too, but to Bahá'ís, those negatives are not the primary, driving force. Love, caring and service to one another are.
Which brings us to this point in human history, when the species is numerous and widespread enough to consider the entire planet as one homeland, and recognize all people as part of one human family. Religion has guided social structure from family, (Abraham) to tribe, (Judaism) to city-state, (Christianity) to nation, (Islam). Bahá'u'lláh, Prophet/Founder of the Bahá'í Faith, brings the next chapter in a divine and ongoing Dispensation. (Bahá'ís believe all seemingly separate religions came originally from the same single Source.)
Timing is everything! The average person living in the time of Moses could not imagine a global civilization, let alone that there were other peoples in the far flung regions of the planet. Some may not even have known there was a planet! Also, communication across large distances was tedious, long or impossible.
Today, most of the physical and technological barriers have been removed. What remains are social walls and disunity, plus a lack of understanding of the underlying purpose of life and of each person's place in it.
The teachings of the Bahá'í Faith address exactly those obstacles and issues. Its laws and guidance are specific to this age in mankind's history, to this level of understanding and to the best way to achieve one human family, living in peace and prosperity in one fatherland, the Earth.