Even the respected elders in the Cretian congregations had to be instructed in basic, righteous behavior. If we're really honest, who doesn't? One of the primary goals of every congregation ought to be to transform our culture to be more biblical.

Paul had high standards for leaders in congregations, but he tried to connect with people how he found them. See Titus 2:9, for example. Slavery isn't desirable, but it's real, and it's not necessarily sinful, and so Paul gave instructions for how to live as a slave.

Everyone should aspire to meet Paul's standards for leadership, but if everyone in a congregation is qualified to be an elder, then they're probably not doing their job of making new disciples.
Titus 2:1-12