Jeremiah 29:7 is used as a theme verse by many missional churches:
Seek the welfare of the city where I have sent you into exile, and pray to the Lord on its behalf; for in its welfare you will have welfare.
Redeemer Presbyterian in Manhattan is one--perhaps the first--of many churches to make Jeremiah 29:7 a rallying cry for Christian engagement with metropolitan culture.
A 2003 sermon by Tim Keller on Jeremiah 29:4-14 finds this description in Redeemer's sermon catalogue:
Jeremiah told the Jewish exiles in Babylon to seek the peace and prosperity of the city they found themselves in. Like New York, it was an enormous, intimidating city with diverse populations that espoused a variety of values and morals. However, God empowers Christians to relate and respond in love to all people, without either assimilating too much to the culture around us or separating ourselves through tribalism. As citizens of both the city of man and the city of God, we work on the principles of peace and grace for the betterment of all.
However, the verse immediately preceding Jeremiah 29:7 is seldom mentioned by churches seeking to justify hip, missional, in-the-city-for-the-city ministry:
Take wives and become the fathers of sons and daughters, and take wives for your sons and give your daughters to husbands, that they may bear sons and daughters; and multiply there and do not decrease. (Jeremiah 29:6)
The context of God's command to seek the peace of the city wasn't a wish that His people enter whole-heartedly into engagement with Babylon's pluralistic society. The context was His desire that they "bear sons and daughters," that they "multiply there and not decrease." Not a call for hipster Jews to become art patrons and tattoo parlor habitues, but for the people of God to bear sons and daughters, to multiply in Babylon and not decrease, to make their homes there and trust Him for the duration of the exile.
It was, most of all, a call to a child-fearing, fertility-averse exiled people to trust Him by bearing children rather than fearing the city and avoiding fertility. Applicable in the same way today? Certainly, though you likely won't hear it in most churches which claim Jeremiah 29:7 as a theme verse. Fear and rejection of fruitfulness walk hand-in-hand today as much as in the exile. God isn't telling the Jews not to fear engagement with alien peoples and alien religions. He's telling them not to fear bearing children in an alien city.
Has a "missional" church ever commended childbearing and fruitfulness in the context of Jeremiah 29:7? Not that I know of. It's more often used to justify art installations than to encourage fruitfulness in God's people. And as such, its use constitutes a sham, a charade, exegetical legerdemain. The first verse you'll never hear: bear fruit, multiply, do not decrease. The second verse has caused a hundred art galleries to bloom.
