When I think about the various religions of the world, I am always reminded of the Latin word, religo, which can mean "to bind fast" or "to moor" (like with a ship or boat).
Using the first definition, we can think religions as something that bind a person to something. That something might be an ideal (like the quest for inner peace), or a divinity (like Yahweh, God, Mother Earth), or even a set of laws (like the Torah of the Old Testament).
Religions also bind people together. Sometimes religious people work together for good purposes; sometimes religious people work together for evil purposes. Thus, in 1999, Steven Weinberg once commented that
With or without religion, you would have good people doing good things and evil people doing evil things. But for good people to do evil things, that takes religion.
Using the second definition of religo, "to moor", I would say that religions also provide people with a sort of mooring or place of anchorage. Religions give people something to cling to or something to aim for. Religions give people some sort of firm foundation to stand upon when the world around them does not make sense. When children die, people often turn to religion. When disaster strikes, people often turn to religion. When people are in trouble, they often turn to religion.
So, I would expect that religions bind people to an ideal, divinity, set of rules, or even to each other; additionally, religions provide people with a place of mooring, a place where they can anchor their mental or spiritual ships.