Here’s the singular principle of Paul that enables Christians to dwell together in unity is to live “to the Lord.” The alternative is to live to the flesh, or as Paul puts it in Rom 14:7-9, “to ourselves.” It is easy to reduce all problems to selfishness, and the reason it is easy is because the accusation penetrates so deeply and explains so much.
To live to the Lord means, in this passage, to live out the death and resurrection of Christ — which means, dying to sin and being made alive to righteousness.

Paul doesn’t really draw out the connection, but living to the Lord means living in light of a final judgment (14:10-12). “For we will all stand before the judgment seat of God.” The logic, as Wright pulls it together, is Jesus was raised, Jesus was raised to be judge, therefore live before the raised Jesus who is also Judge.
I believe the emphasis of many today on the redemption of the world is salutary, and I believe that many have constructed gospel preaching far too much on the “it’s all about heaven” platform, but if we are discovering the former again with renewed force, we can’t do at the expense of the eternal.