The philosopher George Santayana had an interesting take on religion. He disapproved of the notion that a single, underlying essence may be found for all religions worthy of the name "religion". As he saw it, you could not separate a religion from its outward forms without killing it, just as you cannot separate the soul from the body without killing the man. Religions, he said, arise in a specific time and place, out of a specific culture, just as plants arise out of very specific soil. Some plants may be spread across time and space, but some will only grow strong under specific climate conditions, and some will be discarded when they lose relevance for us, as many plants die off when they cease to be cultivated; that is, when men lose interest in them.
While Santayana would admit that multiple religions are in possession of "the truth", I don't think he would say they are in possession of the same truth, but, rather, a truth more or less suitable for the people of a given time and place. For him, it was not possible to strip away the "trappings" of a religion in order to reveal essential universal principles. Rather, those "trappings" are the body of the religion; the legs that move it, the arms that work for it, and so on.
The question arises, for a post-cultural age such as our own -- an age in which many cultures are coming together in a cultural melting pot, -- 'How can we take equally seriously the claims of multiple religions which obviously contradict one another?' How can the world arise on the back of a turtle and out of the belly-button of Vishnu? Solving this paradox is not easy, and it is no wonder that modern seekers sometimes long for a simpler time. Many of us would like to have been born into a culture removed from other cultures, where we could work with the local archetypes without them being "contaminated", or complicated, by the archetypes of other cultures. The saying, "He who tries to follow all paths, gets nowhere," has particular resonance for many of us.
We may consider the proposition, "when in Rome, do as the Romans", and translate this into religious language. Meaning, when in India, be a Hindu; when in Tibet, be a Buddhist. And so on. But we live in a world where even this is no longer possible. India contains both Muslims and Hindus, side by side. America is even more diverse. We are presented with a rather complex choice: 1.) Accept one religion, while knowing that it is, perhaps, no more or less true than another. 2.) Attempt to weave together, from many traditions, a hybrid religion. 3.) Invent an entirely new religion (this may be possible only for men of true vision, capable of creating such worlds inside themselves) 4.) Reject religion altogether.
I have not included the notion of a "spirituality", as distinct from a religion. Many people today are turned off by the mere notion of religion, and prefer something they call spirituality. But my understanding is that, if your spirituality assumes certain practices, beliefs, or forms, then it is a religion. You may not be dogmatic or evangelical about it, and you may even be the only member, but it is still a religion; a specific set of beliefs, practices, and forms (or archetypes). To the extent that your spirituality has no beliefs, no practices, and no archetypes, it is not really anything at all. Here, I am in agreement with Santayana. But then, even nothing is a position. A belief in nothing. A practice of non-practice. An archetype of the "faceless God". For all intents and purposes, an undelineated slough. Even the agnostic has his God, but the God of the agnostic remains unconscious and unarticulated, wandering in the underworld, unable to ascend, unable to catch the daylight.
My feeling is that highly evolved beings will understand that it is possible for men to practice different religions while serving the same God. For instance, in a university there are many classrooms, and many majors. In one room, a person may be studying to become a sculptor, while in the next room a person may be practicing advanced astrophysics. Perhaps, in time, the sculptor will take up astrophysics, or the astrophysicist will take up sculpting, but this is immaterial. The point is, they remain isolated from each other, intent upon their specific course of study.
If the sculptor were to enter the physics classroom, it would be a break from his presently chosen course of study. If he were then to attempt to explain his art to the physicists, they might become irritated. Not because they think he is wrong, but, because he is interrupting their studies. They may have tremendous respect for his work. They may even envy his talent, and secretly wish that they could have been artists. But, on a deeper level, they are content to devote themselves to the course of study in which their own talents and dispositions are honored and utilized.
So it is with religions. Just as a person may experience a calling to be a sculptor, he may experience a calling to be a Christian. For practical purposes, he must value his calling more than he values the callings of others, or else he will never devote himself to anything. At the same time, he must treat the callings of others with respect, and understand that, ultimately, their values are not misplaced. Their values are proper to their own line of work.
Paradoxes may arise, but there is no need to fetishize them. For the Christian, Jesus is Lord, the one true Son of the Father. And this does not contradict the equally valid truth that, for a Muslim, Muhammad is the greatest prophet. If you give your father a hat which reads, "World's Greatest Dad", nobody is offended. Why then should they be offended when you give precedence to your spiritual father?
Every student must have a greater reverence for his own teacher and his own lessons, than for the teachers and lessons of others. This does not prevent him from recognizing that other teachers and lessons may be no less worthy of the reverence of their pupils than his teachers and lessons are for him. This is what it means to be "in the world, but not of it."