There is one common thread, though: the birth of ideas in the minds of human beings. In science, there are several theories and axioms which took birth in the minds of the noble or ignoble humans and either they were proved in later experimentation or were accepted by commonsensical deduction. Modern physics especially, the branches of quantum theories or string theories are but ideas waiting to be proven or accepted. Religion also had its roots in human mind. Dogmas and doctrines, practices are all born out of human intellect: ideas mundane or of great intellect.
Religion thrives and survives on one basic principle: faith. In fact, we often see the faith as a synonym of religion. Faith is a feeling, similar to a belief. What concrete foundation it has is a different matter. Faith is in fact a manifestation of human ideas. If humans were not able to think and form opinions, there would neither be religion, nor science.
Talking of faith, when the faith forms in the obvious in the nature, it becomes the least sensitive part of the religion. For instance, importance of the natural elements like earth, air, water and fire are almost common in most religions. The most sensitive issues that differ between the religions of the world are mostly the convictions which are not natural; not so obvious; the unknown and the unseen and hard to comprehend.
Blind faith is what makes the religions non-scientific. If there was a custom or tradition in a religion that has a proper reasoning or rational behind it, it cannot be considered as a blind faith.
Here also comes the aspect of logic.
With logic, we have one more product of human intellect: the philosophy.
Most of the Western world considers Aristotle as THE Philosopher. However, historically this is not true. Philosophy existed ever since the first of the human species evolved, with a psyche that could make the species "think". There were innumerous civilizations across the world, some of which have lost their stories in eternity and very few have still sustained. There were philosophers in the Greece before Aristotle, even before Socrates or should we say even in the times of Homer or before? India, the country that was the center of interest during the ancient and medieval times for its rich tradition of heritage, has a unique history of philosophy too.
What is the basis of philosophy? Like faith is to the religion, the belief is the crux of philosophy. Philosophy is but a conviction of things and processes around a person. Like religion and science, philosophy also has the natural course of "actions" being performed based on the belief one has.
While there are behavioral traits that draw a line of difference between religion and philosophy, there is also a binding force: the transformation of faith into belief, with reason or without.
Philosophy, religion and science, have all made so much of progress, that the fundamental thoughts have transformed from Individual level to collective level. Hence, today we see many communities- of religious, philosophical and even scientific nature.
The complexity of human thoughts and ideas has influenced, if not originated, the amalgamation of these three different products of intellect. Today, there may be scientific communities with an inclination to a religion and more frequently a philosophy. There are philosophical communities that have some part of their ideas derived on established scientific facts and more frequently, of ideas derived from historical religions.
However, religion embracing scientific facts and/or philosophical propositions that have not existed long before is not witnessed. Perhaps, because religion is the oldest of the these three.
Well, there may be some newly born religions which are based on philosophies and very rarely also on some aspect of science. This yet again proves that religion has its birth in human mind.
What is divinity? Does an entity called God exist? These questions are more of philosophical nature. Religion is formed based on these questions already answered and opinionated. Science does not care to dig into these. And in trying to find an answer for this, innumerate philosophies
have been born. Most of which could be bent over to one or more religions.
So, in a way, philosophy is some where between the two extremes of religion and science.
Human race is not only responsible for the existence of these ideas, but also the sufferers of the consequences of the ideas, as and when they have advanced.
As the faith in the religion has grown so strong that common sense or reasoning has no impact or even consideration, there have been many ill-effects on the human lives. From times immemorial, each religion had its own misgivings. But again, it has to be remembered that the ideas were human, the thoughts were human, the actions were also human, towards or against the human lives.
Advancement in science has its own consequences of human terror. Wars, often aided with military science, have always done damage than good. There are good examples too, like in the fields of medicine, or civilian engineering which has provided almost every aspect of this century's living ways and comforts are products of science. However, there are bad examples, and weapons of mass destruction is just one of them.
Philosophy, although appears not too extreme, depending on the will of the individuals who apply these philosophical thoughts into action, there have been casualties before. Dictators across the world, and supreme leaders, have often with their philosophies have destroyed human lives.
The business of the world today survives more based on what is different than what is common between the peoples. Different people have different needs and different capabilities. If there is absolutely no difference between individuals or countries, nothing would be exchanged.
As long as this exists, the difference, the flow of the activities in the world would be natural.
But, if we wake up in a world, where the populations and individuals have all common interests, all common needs, all common capabilities, imagine if there would be any productivity? No. The key to the world we live in today, is based on the variation of human thoughts, ideas and their subsequent needs.
If there were no religion nor philosophy, but only science, lives of people would be totally mechanical. Men and women would turn into robots.
Religion and philosophy are in a way inseparable. Hence, it is not only difficult but also silly to imagine a world with either one of them without the other.
The relationship between the two lies in the basic fundamental synonymous relationship between faith and conviction.
Ideas, thoughts will still remain the common ground of these three interesting aspects of the human civilizations.