Because the division caused by sin is an all-encompassing division—cutting us off from God and, therefore, from each other—the gospel is an all-encompassing remedy. Jesus’s atoning work reconciles us to God but it also reconciles us to each other. Or, rather, it should. The gospel creates the culture of reconciliation, which the New Testament calls the church.
As long as the focus is on reconciliation, it will not fully happen. The focus must be on Christ, as in the old triangle marriage illustration.