Allen Yeh, a Professor at Biola Univeristy and tutor in the Torrey Honors Institute, has written an article in which he argues that missions is the central theme of Christianity.  The Bible, he says, is a means to an end, and that end is missions.

He offers many reasons for his choice of missions, such as the fact that all of the Apostles were missionaries, Jesus' lasts words on Earth were a call to missions, there is a whole book (Acts) devoted to chronicling missionary activites (and on top of that, most of Paul's letters are written in a missionary context), etc. 

Now, I agree with nearly everything that Dr. Yeh says.  Missions is an extremely important biblical theme, and it's one that can tend to be denegrated among academic theologian types (like myself).  At one point, Yeh comments, "The center of gravity of Christianity has shifted away from the Western world, and most of the Christians in this world are now in Asia, Africa, and Latin America."  This is no small matter.  Christianity is incurably multi-cultural and this is a direct result of its missional nature.  But is "missions" in and of itself really the "central theme" of Christianity?  If the Bible is a means to missions, might we ask if missions isn't a means to something else?

Yeh does stop to mention a few other candidates:

scholars have proposed various possibilities for what might be the main theme of the Bible. Some people say it’s the Kingdom of God. Some say it’s God’s sovereignty. Others say it’s God’s love. Still others say it’s worship (one of the most famous proponents of the last is John Piper, as he says in his book Let the Nations Be Glad: The Supremacy of God in Missions, “Missions exists because worship doesn’t”). Other possibilities include: the two Greatest Commandments (love God and love neighbor); the Great Commission (there are actually five Great Commissions, one in each Gospel and one in Acts); the Covenant; the Promise; and the glory of God. While I think all of these are valid, again I would argue that it is only mission that adequately encompasses all of these.


Later on, referring back to the reference to John Piper above, Yeh says:


One of the four identifying hallmarks of evangelicals is a priority on spreading the Good News... The articulation of this Good News is simply this: that God loves you, to the point that he would send his Son to die for your sins, and you ought to worship Him in response. As such, in contrast to Piper’s quote above, I would say that mission is not a predecessor to or separate from worship, but rather it is the first act of worship.

Now it is here that I beleive Dr. Yeh falls into a common error that has plauged evangelicalism for a long time.  He places the proclaimation of the gospel exclusively in the realm of missions.  It is easy to see, then, why missions itself would become the central theme of the Bible.  A few paragraphs later, he says, "In most Protestant churches, the central part of the worship service is the sermon. The original function of the sermon was evangelism, as seen in the Greek word kerygma which means “proclamation” (of the Good News)."  Again, proclaimation of the good news is used here as a synonym for evangelism.  But this not how the Biblical authors treated the gospel.  Paul, in his letter to the Romans, begins (in chapter 1, verse 8) by thanking God for the church in Rome, because their "faith is proclaimed in all the world."  They are Christians (and apparently Christians of amazing faith) not pagans in need of evangelism.  And what does Paul go on to do?  In verse 15 he says, "So I am eager to preach the gospel to you also who are in Rome."  The first thing Paul does is proclaim the good news, to those who are already Christians.  This is how the gospel is treated in Scripture.  It is not a one-time bit of useful information that, once responded to, is no longer necessary.  It is the heart and soul of all Christian teaching and worship.  This is something that the Reformers recognized, which is why the sermon did become so central to Protestant Christianity.  Thus it would probably be better to view Missions and the local church worship service as two seperate but equal "pillars" that are the foundation of Christianity.  Both are important, both are commanded by Christ, and both are acts of worship that encompass all the myriad themes found in the Bible.  Theologians may have a tendency to forget about the unreached (except as an abstract theological concept in their systems), but missiologists can also have a tendency to forget about the reached! 

I also think Piper's comment is worth returning to, because I think Yeh may have misunderstood it.  When Piper says, "Missions exists because worship doesn’t", I doubt that he's trying to say that worship per se is the central theme of Christianity.  Once again, worship is a means to an end, and that end is to glorify God.  It seems to me that missionary activity is also a means to an end.  It is a means to bringing people to Christ, allowing them to come into his presence and worship Him, and ultimately spend eternity with him.  And as Yeh pointed out, missions can itself be an act of worship, which would in turn be an act of glorifying God.  Thus missions is not only an act of glorifying God in itself, but a means to the end of furthering God's glory throughout the world.  This is probably what Piper is getting at, and it seems to me to be the best understanding of the true central theme of Christianity.  Yeh is right to stress how important missions is, but we must always remember WHY it is so imporant (for the glory of God).