The benediction in Romans 15:5-6 is one way of stating God’s aim for His people.
May the God of endurance and encouragement grant you to live in such harmony with one another, in accord with Christ Jesus, that together you may with one voice glorify the God and Father of our Lord Jesus Christ. (Romans 15:5–6, ESV)
Not only do we see God’s goal for us, but we also see how difficult it is for us to get there. In order to “live in harmony with one another,” in order to glorify God “with one voice,” God must grant it. We cannot do it in our own strength. We don’t have the endurance for Project One Voice, so the “God of endurance” must help. We’re likely to be discouraged by a gangly body part that rubs us the wrong way, so the “God of encouragement” must help. In fact, we won’t even want to be in this community choir unless God saves us by the gospel. He has to overcome our pride and selfishness all along the way in order to teach us to sing together.
We can’t do it on our own, and yet we must do it.
Therefore welcome one another as Christ has welcomed you, for the glory of God. (Romans 15:7, ESV)
We must “welcome,” we must seek “not to please ourselves,” but “let each of us please his neighbor for his good, to build him up” (verses 1 and 2). This is God’s goal for us in the gospel and our failure to do it is sin. You know who makes it hard? Me! I’m still in process of considering myself dead to sin and alive to God in Christ Jesus! So are you. But that’s no problem. That’s why we love the gospel.
We work against God when we will not endure the “failings of the weak.” We image some other Christ when we reject rather than receive one another. We’re not supposed to embrace others because they deserve it, but because we’ve been welcomed by Christ.
What God is after is what we fail at. What we fail at is what we should repent from. And what we repent from is what God helps us get after. The God of endurance and encouragement grants us strength, and that may start with granting us the strength to repent.