There is one God

but many limited conceptions and representation of god.
the errors of all religions until now, stem more or less, from such limited understandings.

for example one such great error stems from the masculine bias upon the conceptions of god in religions such as christianity.
the christian trinity is in fact formed from divine father and divine mother and the product of their love: son/child.

a pretty clear explanation of this:

"I have met many people who are extremely sophisticated culturally and intellectually, and are in possession of undoubted spiritual experience, yet they have been surprised, even appalled, at the very idea of what they perceived to be the projection of gender and human categories in general onto worlds of the highest reality, even onto the mystery of God Himself. They considered it a vestige of the ancient tendency of the limited human mind to anthropomorphize the spiritual. Incidentally, the Islamic objection to the belief in the Trinity and to the cult of the Mother of God derives from quite similar (psychological) sources. It is for the very same reason that deism and contemporary abstract cosmopolitan monism reject so vehemently belief in the Trinity, in hierarchies, and, of course, in Eternal Femininity. Ridiculous as it may seem, even the charge of polytheism that Muhammad leveled at Christianity thirteen hundred years ago has been reiterated.
Such charges are rooted either in an oversimplified understanding of Christian beliefs or in an unwillingness to penetrate deeper into the question. There has been no projection of human categories onto the Divine in historical Christianity, let alone in the worldview of the Rose of the World, but something in principle quite the reverse. No one is questioning the oneness of God, of course. It would be naive to suspect anyone here of reversion to the age of Carthage, Ur, and Heliopolis. The hypostases are separate external manifestations of the One Essence. They are how He reveals Himself to the world, not how He exists within Himself. But God's external manifestations are just as absolute in their reality as His existence within Himself. Therefore, the hypostases should not in any way be taken for illusions or aberrations of our mind.
In manifesting Himself externally, the One God reveals His inherent inner polarity. The essence of that polarity within the Divine is transcendental for us. But we perceive the external manifestations of that essence as the polarity of two principles gravitating to each other and not existing one without the other, eternally and timelessly united in creative love and bringing forth the third and consummating principle: the Son, the Foundation of the Universe, the Logos. Flowing into the universe, the Divine retains that inherent polarity; all spirituality and all materiality in the universe is permeated by it. It is manifested differently at different levels of being. At the level of inorganic matter perceptible by humans it can no doubt be seen as the basis of what we call the universal law of gravity, the polarity of electricity, and much more. In the organic matter of our plane here, the polarity of the Divine is manifested in the distinction between male and female. I wish to stress that it is manifested thus here, but the polarity of the Divine that is the basis for that distinction cannot be comprehended in itself, in its essence.
That is why we call Divine Femininity the Mother of Logos, and through Him, Mother of the entire Universe. But the eternal union between the Mother and Father does not change Her timeless essence. It is for that reason that we call the Mother of Worlds the Virgin.
Thus, one does not discern in the teaching on the Trinity and the Feminine Aspect of the Divine the projection of thinking that is "all too human" onto the cosmic realms. To the contrary, the teaching represents an intuition of the objective polarity-the male and female-of our planes as a projection of the transcendental polarity within the essence of God.
"God is Love," said John. Centuries will pass, then eons, then finally bramfaturas and galaxies, and each of us, sooner or later, will reach Pleroma- divine Fullness-and enter the beloved Heart no longer as a child only but as a divine brother as well. All memory of our current beliefs about the Divine will vanish from our mind like pale, dull shadows we no longer have any need for. But even then the truth that God is Love will continue to hold. God does not love Himself (such a claim would be blasphemy), but each of the Transcendencies within Him directs His love onto the Other, and in that love a Third is born: the Foundation of the Universe. Thus, the Father-the Virgin Mother-the Son."


This does not mean that chrstianity or other religion do not express a spiritual truth. In fact they do. There is only one transcendental god.
Just that the limited humans mind which conceived the dogmatic view upon what is the truth about such god, were limited and were based on human misconceptions and limitation (e.g. patriarchal bias).

Older polytheist systems do not even grasp this transcendental truth of oneness.

But human mind reached the necessary level in evolution, to understand the interplay between one essence and a multitude of manifestations of that essence, which are meta-culturally and subjective expressions of transcendental truths.

Truth is one, but anyone has the freedom to express that truth in any way he wishes. One transcendental god, but toleration for every opinion of how that god be conceived personally.

This is what a one living in the spirit of Christ does. True tolerance. The spirit of christ is just one of many manifestations of the Spirit.
any culture in the history of humanity, had at some level such a manifestation of Spirit
and any true seeker understood these basic facts.
one who claims to be christian or believer in any other religion, but fails to understand and apply in life this basic truth of tolerance, commits sin against Spirit.