Worldview gap: secular view — people are generally good and deserve heaven; biblical view — the opposite

When a Christian says "what you're doing is sin," a person operating from the secular worldview (people are generally good and deserve heaven) hears it as: "You are one of the bad ones and I am righteous." But the biblical view is that everyone is a sinner — so the Christian is saying: "You're a sinner like me. We're in this together. We both need Jesus."