From David Platt's book, "Radical". Check out Part 1, 2, and 3. This section is tied directly to Part 3 where David is talking about the question, "What about the needs here?"

It's 6,783,421,727 and counting. As I write this chapter, this is the population of the world. According to the most liberal estimates, approximately one-third of the world is Christian. These estimates include all who identify themselves as Christians, whether religiously, socially, or politically. Likely, not all of them are actually followers of Christ. but even if we assume they are, that still leaves 4.5 billion people who, if the gospel is true, at this moment are separated from God in their sin and (assuming nothing changes) will spend eternity in hell.

Again, 4.5 billion.

And most of them live outside the United States.

In light of all that we have seen in Scripture, certainly God has given us his grace to extend his glory not just to areas of need here but to areas of need around the world. Not either here or there, but both here and there.

In all this missions talk, you may begin to think, Well, surely you're not suggesting that we're all supposed to move overseas. That is certainly not what I'm suggesting (though I'm not completely ruling it out!). But this is precisely the problem. We have created the idea that if you have a heart for the world and you are passionate about global mission, then you  move overseas. But if you have a heart for the United States and you are not passionate about global mission, then you stay here and support those who go. Meanwhile, flying right in the face of this idea is Scripture's claim that regardless of where we live—here or overseas—our hearts should be consumed with making the glory of God known in all nations.

I know there are probably some folks in the church I pastor who wouldn't mind if I left and lived in another nation. I say this kiddingly (I hope!), but, after all, isn't that where people who are passionate about the world go? But this is exactly why the church I pastor is stuck with me (as long as they'll have me). Because from cover to cover the Bible teaches that all the church—not just select individuals, but all the church—is created to reflect all the glory of God to all the world. Because every single man, woman, and child in the church I pastor is intended to impact the nations for the glory of Christ, and there is a God-designed way for us to live our lives here, and do church here, for the sake of people around the world who don't know Christ.

So what is this God-designed way to live? All this talk about having a heart for the world may sound a bit cliche and even seem a bit hollow, but what does it mean to live for the glory of Christ in all nations?