Imagine what an overgrown jungle Paul’s conscience was the day he became a Christian, packed not only with all of God’s good laws but also with cultural scruples and hundreds of unnecessary rules from his life as a Pharisee. But at some point he opened the gate to Jesus and said, “It’s yours, Lord. Tell me what stays, tell me what goes, and tell me what’s missing.” Such careful cultivation of conscience allowed Paul eventually to be able to say, “I have become all things to all people so that by all possible means I might save some” (1 Cor. 9:22).
Where do you get missionaries like Paul, who have done the hard work of tending their conscience so they can navigate difficult cultural situations without exporting cultural Christianity? You grow such missionaries in the church, which is God’s laboratory for learning how to reach other cultures.
The Bible gives clear evidence that God intends the little clashes of culture in your church to prepare you for the really difficult clashes of culture in missions and evangelism. The local church is supposed to be that laboratory.
There are so many Christians in America that we have the luxury of dividing up into smaller and smaller subsets so we can be part of a church where members hold very few differences on matters of conscience. We even enshrine some of those scruples in our bylaws to guarantee unity—or, more accurately, uniformity.
Ultimate Cross-Cultural Missionary
Twice in Scripture Paul deliberately connects (1) the messiness of getting along in church with those with different consciences to (2) mission to the unreached. One is the famous “all things to all people” passage in 1 Corinthians 9:19–23, in which he defends his own cultural flexibility in order to win as many as possible among groups with differing scruples.
But this famous missionary text comes right in the middle of Paul’s exhortation to the Corinthians to be sensitive to the weak consciences of others in their church (1 Cor. 8 and 10). Flexibility in church life gets you ready for flexibility in missions.
Even clearer is the link Paul forges in Romans 15, the most important missions passage in what is arguably Christianity’s most important theological document. Romans 15 is the soaring description of the worldwide mission of the church. And who is the cross-cultural missionary par excellence? The Lord Jesus Christ, who became a servant to a people and culture not his own. That’s Romans 15.
Romans 14, on the other hand, teaches how to handle church disagreements about scruples. What could these two topics possibly have in common? Paul forges an unbreakable connection between them, a connection that will help us become more effective churches, evangelists, missionaries, and churches.
The link comes in Romans 15:7, where Paul summarizes everything he’s taught since Romans 14:1 about getting along with those in your church who have different scruples. Notice the key connecting word “For”:
Therefore welcome one another as Christ has welcomed you, for the glory of God. For I tell you that Christ became a servant to the circumcised to show God’s truthfulness, in order to confirm the promises given to the patriarchs, and in order that the Gentiles might glorify God for his mercy. (Rom. 15:7–9)
Do you see the connection? Verse 7 tells you to learn to love, welcome, submit to, and reach out toward those in your church who are different from you. Why? Because (v. 8) that’s what Jesus did when he left heaven to be born as a Jew, to become a servant to Jewish culture so that the whole world could be saved.
The Son of God Was Not a Jew
Ponder this: The eternal Son of God, who wasn’t a Jew (it says he became one), left complete freedom in heaven to became a good little Jewish boy and then a good, law-keeping Jewish man. The whole time he obeyed the laws he himself had given at Mount Sinai—even obeying laws he knew were temporary since he designed them so (e.g., avoid pork, worship only in Jerusalem). The only laws Jesus pushed against were those the Pharisees and others had either added or completely misunderstood.
Jesus practiced what he later preached through Paul in Romans 14. He became a servant to people different from him. He submitted himself to a culture foreign to him. Jesus wasn’t some countercultural hippy railing against everything traditional. He wasn’t a weird outsider or misanthrope. He went to synagogue with his parents, and to the temple when he was 12. He regularly celebrated Passover and other Jewish feasts. He rested on the weekly Sabbath and attended synagogue service. He became a servant to the Jews and their culture.
What happens when people do things like that? What did the Son of God purpose to accomplish when he voluntarily became what he was not—a servant to a particular culture not originally his own? We’ll number Christ’s purposes within the text.
Therefore welcome one another as Christ has welcomed you, for the glory of God. For I tell you that Christ became a servant to the circumcised  to show God’s truthfulness,  in order to confirm the promises given to the patriarchs, and  in order that the Gentiles might glorify God for his mercy. (Rom. 15:7–9)
1. Christ became a servant to the Jews to show the world God is truthful.
Christ’s first purpose was Godward, to vindicate God’s truthfulness. Had the Son of God not become a servant to a culture not his own, this would never have happened.
2. Christ became a servant to the Jews to fulfill all God’s promises to the patriarchs.
Think of all God’s promises in the Old Testament, hundreds of them. Their fulfillment depended entirely on Christ’s becoming a servant to a culture not his own.
3. Christ became a servant to the Jews in order to bring the Gentiles into God’s family.
None of the four Old Testament promises about Gentiles in the following verses (Rom. 15:9–12) would have come to pass had Jesus not become a servant to a people and a culture not his own.
Jesus led the way in serving a people and culture not his own—laying down his life for those so different from himself. Now he summons you and me to do the same.
Uncomfortable clashes of culture and conscience are unavoidable in our churches. But God wants to use them to prepare us for the more difficult clashes of culture and conscience when we take the gospel to the other side of town—and the other side of the world.
Editors’ note: This is an adapted excerpt from Andy Naselli and J. D. Crowley’s new book Conscience: What It Is, How to Train It, and Loving Those Who Differ (Crossway, 2016).