Similarly I'm not arrogant enough to say that I "know" god doesn't exist.
Many people are that arrogant, and they want you to think they are like you.
You realise that religion as we understand it predates the word "religion", right? And that how a word was originally applied centuries ago doesn't define its current usage?
There's a real philosophical question about whether a man-made entity can predate the word to describe it, but more important than that, you're systematically rationalizing away any avenue of criticism. I can't tell you what the word means, cause that's just what some people now want you to think. I can't show you the word has always meant that, because it doesn't matter what it used to mean. Shall I go down every definition google presents?
- the belief in
and worship of a superhuman power or powers, especially a God or gods.
- a particular
system of faith and worship.
- a personal set or
institutionalized system of religious attitudes, beliefs, and
practices
- the
service and worship of God or the supernatural
- a range of
social-cultural systems, including designated behaviors and practices, morals, beliefs, worldviews, texts, sanctified places, prophecies, ethics, or organizations, that generally relate humanity to supernatural, transcendental, and spiritual elements
- a set of beliefs concerning the cause, nature, and purpose of the universe, especially when considered as the creation of a superhuman agency or agencies, involving
devotional and ritual observances, and often containing a moral code governing the conduct of human affairs.
How many definitions will it take to convince you that religion is defined by practice as much as belief?