“Religion is another name for the realization of Truth. It consists in becoming and being one with the Supreme Being. Doctrines and dogmas are only details of a secondary nature.”

"Likeness to God", an address in Providence, Rhode Island (1828) http://www.americanunitarian.org/likeness.htm
Context: I affirm, and would maintain, that true religion consists in proposing, as our great end, a growing likeness to the Supreme Being. Its noblest influence consists in making us more and more partakers of the Divinity. For this it is to be preached. Religious instruction should aim chiefly to turn men's aspirations and efforts to that perfection of the soul, which constitutes it a bright image of God. Such is the topic now to be discussed; and I implore Him, whose glory I seek, to aid me in unfolding and enforcing it with simplicity and clearness, with a calm and pure zeal, and with unfeigned charity.

[2008, Christianity / Islam, World Wisdom, 141, 978-1-933316-49-9]
Spiritual path, Wisdom

The Uttarpara Address (1909)
Context: That which we call the Hindu religion is really the eternal religion, because it is the universal religion which embraces all others. If a religion is not universal, it cannot be eternal. A narrow religion, a sectarian religion, an exclusive religion can live only for a limited time and a limited purpose. This is the one religion that can triumph over materialism by including and anticipating the discoveries of science and the speculations of philosophy. It is the one religion which impresses on mankind the closeness of God to us and embraces in its compass all the possible means by which man can approach God. It is the one religion which insists every moment on the truth which all religions acknowledge that He is in all men and all things and that in Him we move and have our being. It is the one religion which enables us not only to understand and believe this truth but to realise it with every part of our being. It is the one religion which shows the world what the world is, that it is the Lila of Vasudeva. It is the one religion which shows us how we can best play our part in that Lila, its subtlest laws and its noblest rules. It is the one religion which does not separate life in any smallest detail from religion, which knows what immortality is and has utterly removed from us the reality of death.

Source: The Labyrinth of Solitude and Other Writings

Your Thought and Mine
Context: Your thought advocates Judaism, Brahmanism, Buddhism, Christianity, and Islam. In my thought there is only one universal religion, whose varied paths are but the fingers of the loving hand of the Supreme Being. In your thought there are the rich, the poor, and the beggared. My thought holds that there are no riches but life; that we are all beggars, and no benefactor exists save life herself.

"The Beauty of the World" (c.1725), from the notebook The Images of Divine Things, The Shadows of Divine Things, The Language and Lessons of Nature (published 1948).

Source: LSD : My Problem Child (1980), Ch. 11 : LSD Experience and Reality
Context: It could become of fundamental importance, and be not merely a transient fashion of the present, if more and more people today would make a daily habit of devoting an hour, or at least a few minutes, to meditation. As a result of the meditative penetration and broadening of the natural-scientific world view, a new, deepened reality consciousness would have to evolve, which would increasingly become the property of all humankind. This could become the basis of a new religiosity, which would not be based on belief in the dogmas of various religions, but rather on perception through the "spirit of truth." What is meant here is a perception, a reading and understanding of the text at first hand, "out of the book that God's finger has written" (Paracelsus), out of the creation.
The transformation of the objective world view into a deepened and thereby religious reality consciousness can be accomplished gradually, by continuing practice of meditation. It can also come about, however, as a sudden enlightenment; a visionary experience. It is then particularly profound, blessed, and meaningful. Such a mystical experience may nevertheless "not be induced even by decade-long meditation," as Balthasar Staehelin writes. Also, it does not happen to everyone, although the capacity for mystical experience belongs to the essence of human spirituality.

What is Religion? (1893)
Context: I think nothing is religion which puts one individual absolutely above others, and surely nothing is religion which puts one sex above another. Religion is primarily our relation to the Supreme, to God himself. It is for him to judge; it is for him to say where we belong, who is highest and who is not; of that we know nothing. And any religion which will sacrifice a certain set of human beings for the enjoyment or aggrandizement or advantage of another is no religion. It is a thing which may be allowed, but it is against true religion. Any religion which sacrifices women to the brutality of men is no religion.

Source: The Moral Judgment of the Child (1932), Ch. 2 : Adult Constraint and Moral Realism