I regularly eat, and regularly think about eating but I'm not religious about food nor do I subscribe to any food religion. I would call regularly doing something a habit. I have an eating habit. Here's the definition of religion and habit from the free dictionary, the majority of meanings clearly describe formal religions (Christianity, Buddhism, etc.)
re·li·gion (r-ljn)
n.
1.
a. Belief in and
reverence for a supernatural power or powers regarded as creator and governor of the universe.
b. A personal or
institutionalized system grounded in such belief and worship.
2. The life or condition of a person in a
religious order.
3. A set of beliefs, values, and practices
based on the teachings of a spiritual leader.
4. A cause, principle, or activity
pursued with zeal or conscientious devotion.
hab·it (hbt)
n.
1.
a. A recurrent, often unconscious pattern of behavior that is acquired through
frequent repetition.
b.
An established disposition of the mind or character.
2.
Customary manner or practice: a person of ascetic habits.
3. An addiction, especially to a narcotic drug.
4. Physical constitution.
5. Characteristic appearance, form, or manner of growth, especially of a plant or crystal.
6.
a. A distinctive dress or costume, especially of a religious order.
b. A riding habit.
Ontologies are like assholes - everybody has one, and voicing them tends to annoy other people.
What the believers are referring to in this thread as religion or worldview, is actually the ontological construct from which one frames the universe, and thus their perceptions of it. I have a slightly different understanding of what religion is. To me, a religion is anything you do religiously. For many of us here, that would include posting on RPFs. I get my understanding from James, who describes pure religion as visiting (helping) orphans and widows, and keeping oneself from being corrupted.
Someone who looks at pornography every day has a religious habit of viewing porn. People can religiously feed their dogs and cats.
To go to (one of the) OP's questions, the reason religion is inseparable from an ontological construct that includes an eternal realm (afterlife) or God, is because belief in such things necessitates the devotion of some regular attention to that issue, whether that be in quiet contemplation, scriptural study, or regular gatherings at a Church or a Synagogue. If regularity is the condition of religiosity, ie regimentation, which I believe it to be, then the mere fact that one regularly contemplates the afterlife makes that in and of itself a religious practice.
See, that is what I believe James calls religion, and I believe James was inspired of God to say such a thing. So my definition of religion is different than everyone in this thread, different even than Merriam Webster. What the dictionary, and my believing colleagues in this thread are calling 'religion,' I call 'ontology.' And literally, every human being that draws breath has an ontology.
In short, one's ontology is their theory of existence.
"I think, therefore I am" is an ontology. "I annoy others, therefore I am" is another (classical!!) ontology. "God created the heavens and the Earth, and on the sixth day God created man, therefore I exist" is another ontology.
One of the problems in this thread is not rules for debate, but the fact that the different parties are coming into it with radically different premises. In order to have a rational discussion of anything you first have to agree on some premises or at least one premise. Without that agreement, we are working from radically different languages. Or, to put it another way, you have a map of Ontario and I have a map of England, and we are arguing over how to get to London.