“Spirit” is the experienced aspect of the not-self and of the world through the not-self mind. Spiritual practices are those technologies of self designed to cultivate the experienced aspect of the not-self.
“Religion” is the central orientation around which one lives one’s life and experiences the world. Today, in mappo, in Kali Yuga, the most commonly practiced religion in the modernized world is The Religion of Me (the experience of the world through the Ego Tripartite Mind). All Religions of Me are based in the catalyst of unreconciled fear. This remains true whether the specific denomination is The Religion of Pleasure, The Religion of Being Entertained and Distracted, The Religion of Never Dying, The Religion of Happiness, The Religion of Peace, The Religion of Material Capital Accumulation, The Religion of Social Capital Accumulation, The Religion of Cultural Capital Accumulation, The Religion of Scientisim, The Religion of Highest Human Performance Potential, or The Religion of Power, etc.
A religion is spiritual only when it is centrally oriented around the experienced aspect of the not-self. This remains true even if historically a religious tradition was at one time spiritual but is now no longer such. Meaning, a religious tradition may have historically been spiritual at one time but can and often will degenerate through the unreconciled fear of its practitioners into a Religion of Me. Thus, there can be and will be throughout the historical record, for example, Christian denominations, Buddhist denominations, and Aikido denominations, etc., that are not spiritual at a given time. There can also be and will also be, again for example, Christian, Buddhist, and Aikido practices, etc., that are not religious - that are not centrally orientating in a practitioner’s life and/or nor displacing of fear centrality. As such, there can be, again for example, an Aikido, etc., that is and will be part of a Religion of Me.