Quotes: What makes an idea sacred or religious?

Theism? Superstition? Myth? Ritual?

Does it have to teach a fixed dogma, and/or does it have to be undefined and flexible enough to allow for its continuous development and for individuals' ongoing learning?

If it is inherently motivated by politics or if it grows to seek political goals, does it have to contain material that is separate from and more enduring than the political movement?

Michael Ducey in 1977 distinguished “mass ritual” and “interaction ritual” based on whether the audience participates.
(Referenced in William Beers. Women and Sacrifice: Male Narcissism and the Psychology of Religion. Detroit: Wayne State University Press, 1992. p. 164.)

Thought becomes religious when it thinks itself out to the end.
Albert Schweitzer

The psychologist Philip Tetlock(1999, 2003, 2004) identifies values as sacred when they are so important to those who hold them that the very act of considering them is offensive.
Daniel C. Dennett. Breaking the Spell: Religion as a Natural Phenomenon. New York: Penguin Group, 2006. p. 22.

To the rational mind there can be no offense, no obscenity, no blasphemy, but only information of greater or lesser value.
Jennifer Diane Reitz, www.transsexual.org

Then what is religion? If you have wiped the window cleant — which means that you have actually stopped performing ceremonies, given up all beliefs, ceased to follow any leader or guru — then your mind, like the window, is clean, polished, and you can see out of it very clearly. When the mind is swept clean of image, of ritual, of belief, of symbol, of all words, mantrams and repetitions, and of all fear, then what you see will be the real, the timeless, the everlasting, which may be called God. But this requires enormous insight, understanding, patience, and it is only for those who really inquire into what is religion and pursue it day after day to the end.
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Religion is the feeling of goodness, that love which is like the river, living, moving everlastingly. In that state you will find there comes a moment when there is no longer any search at all; and this ending of search is the beginning of something totally different. The search for God, for truth, the feeling of being completely good — not the cultivation of goodness, of humility, but the seeking out of something beyond the inventions and tricks of the mind, which means having a feeling for that something, living in it, being it — that is true religion.
J. Krishnamurti. Think on These Things. ed. by D. Rajagopal. New York: Perennial, 1964. pp. 43, 157.