To me, family includes at least three kids, a station wagon or minivan to hold them and all their soccer gear and their five best friends, and a devoted circle of support crew other than myself.
I wouldn't necessarily have to have the kids as my biological children. Right now I've got a darling four-year-old who calls me Aunt. He is family, as is his mother, as is our other roommate who's going to start getting called Uncle any day now; we've got Uncle Darkside and Uncle Alan as well. We're a family, though Uncle Darkside doesn't spend as much time with the family as he might. There's the other roommate's girlfriend, who spends significant time here; she's joining the family.
Even online presences are significant in my idea of family -- my nephew often sits down on my lap and helps me talk to "my" David. "Who's that?" "It's *my* David." "Let me talk to David! Spell my name!"
It's family, though our religion is generally a mix of "other," and no one is married to anyone else or, with the exception of Sis and her son, biologically related to anyone else.
It's family. I get the idea that, like a Heinlein family, people and cats will just keep marrying in, or just joining in, and we'll have to get a house big enough for us all. I was raised with the Heinlein ideal of a family: central to the family are the kids and parents, and then other people just sort of congregate around the cluster of the family nucleus, however many kids/parents there may be. Parents don't necessarily have any biological role; I would be at this point my nephew's other "parent;" the new roommate would be the third. Alan will always be "Uncle Alan," and so will Uncle Darkside.
Religion is definitely a tie that holds this family together. After all, how did I meet my sister? How did I meet Uncle Darkside? How did I meet Alan? and the new roommate? Mostly, we do our own thing religiously, since we do recognize the inherent differences in our specific paths of faith, but it's an open thing in this household. You don't have to scuttle off to a corner to do whatever it is you're going to be doing, unless whatever it is that you're doing calls for privacy.
This is a family, as I've never had it before. My biological family was more independant, though we did do things together as a family before I hit my teenage years and we all split and went our own ways. But they allowed me to go my own way; they did not force me into their ideals of what was correct.
I want a family as good as the one I grew up with, when I go to start my own, and it looks like I've got a good start on one right now.