The word of the day is "collectivism." As opposed to "individualism."
Now, I actually don't know if "collectivism" is the best word for the paradigm governing the lives of the biblical writers. To at least a few, this will immediately evoke images of Soviet era communism and totalitarian oppression. This is not an uncommon objection, I've discovered when talking about this matter. So I'm not really stuck on the word "collectivism." Maybe "corporatism" would work better. Or maybe just "union." Anyway, the point is, people in the Bible generally aren't running around concerned with their "personal relationship with God" as we're often led to believe. Rather they see themselves as folks who belong to a wider "people" which has a corporate relationship with God, which has been effected by the singular salvation of God. And they're very thankful for the God of Israel's redeeming work in history, and that they get to be a part of this people which he saved and preserved for himself. So let's not make the mistake of thinking this produces a less personal response in the individual.
But one thing that strikes me as telling, is that one of the most common go-to qualifications, if you will, to the notion that the sweep of Scripture is telling us about a "people of God" dwelling with God (rather than about "my personal salvation") is that we must be careful not to say that one can "be saved" by joining a church.
Now, aside from the fact that what's usually meant by "personal salvation" is the believer's eternal, post-mortem destiny, which is not a good place to start with the word "salvation..."
...aside from that, this objection brings us right back around to the very reason we need to hear the correction in the first place- that we're far too individualistic in our concept of salvation and relationship with God! So if we hear that the overwhelming number of references in the Bible to God's people is in the singular, and our primary objection is that "one must be saved individually," We've slipped right back out of alignment before even hearing the content correctly. This just betrays how badly this correction is needed.
Doesn't it? Because "individual salvation" is an imported emphasis. To my knowledge, nothing in Scripture tells us that the saved individuals of, say the book of Acts, conceive of their salvation as a personal, individual thing. They conceive of it as God's, and as something that has been effected for his people as a whole (that's how Jews thought, after all). And they have personally walked into this grand unified sweep of God's salvation.
Salvation ought to be thought of not in terms of its "individual personalness" but in terms of what God is doing for the world, in the world, and for the people of God. It's calculated in terms of the the goal of the oneness of the community, in Christ. This doesn't mean people come to salvation by becoming part of some de-humanizing hive-mind. It means that no one obtains a salvation that is not for the entire group. Imagine that- there is no such thing as "personal salvation!" And here I spent so many years trying to feel grateful, or emotionally responsive, about my personal whatzits that God had given to me individually. But it's simply not enough to conceive of it this way. The Christian church has not experienced a bazillion personal salvations, which just happen to form a community afterwards. The Christian church has experienced one salvation!
If we're simply trying to ward off some notion that salvation happens by joining a church, let's deal with that when we get there. But if you were planning on leaving membership in the Church out of your definition of salvation, I think you'll find that it's a problematic as well. You don't "get saved" and then as a result of that, "go to church." You "get saved," and the very definition of that salvation includes membership of a body, the Body of Christ. Church isn't something you do once you're saved, it's something salvation creates. And conversely salvation doesn't merely concern where an individual is going when they die, it concerns how they relate with God and the people of God now. So if you're talking about a salvation that doesn't by its nature create a unified body in the present, you're not really talking about Judeo-Christian salvation.
Thus when Paul tells the church in Ephesus: