The second verse of the sidra reads, “When any one (singular) of you brings an offering to HaShem, you (plural) shall bring your offering” (Lev. 1:2). The change surely implies that when a individual does the right thing, the whole community derives benefit.
An analogy is offered by the Midrash. “Why,” it asks, “is Israel compared to a lamb? Just as a lamb may be hurt in any part of its body and all its limbs feel the pain, so with Israel: if one Jew sins, all the people feel it.”
Rabbi Shimon ben Yochai now offers the famous parable: “A group of people are sitting in a boat. One takes an axe and begins chopping at the floor. The others cry in horror, ‘What are you trying to do?’ The man answers, ‘What business is it of yours? I am doing this to my part of the boat!'” (Vayikra Rabba 4:6).
Whatever happens in society we are in it together. Let one person act irresponsibly and we all suffer; let one do a mitzvah and we all benefit.
Unfortunately this is both a lateral and a vertical problem. It is lateral – what you do now has effects across the board. It is also vertical – what previous generations did still affects us now, for good or for ill; and what happens in our age can have consequences for centuries to come.
The way life works, no-one can say, “What business is it of yours what I am doing?” Everyone is in the same boat, now and throughout history.