What is "Mission"?

I just bought this book by John Stott about missions: Christian Mission in the Modern World. (Weird, mine has a different cover than the one I linked, and I just bought it from Amazon.) Usually I don't get very far in non-fiction books, but John Stott obviously knows how to write a completely readable theological work. ;)

Anyway, I've only finished the first chapter but already have a lot to think about... and be excited by. Here's an example; this is after comparing a couple views of evangelism and social action (social work as a sugar-coating for the gospel, or the gospel leading to "good works" as part of evangelism, or this):

Neither one [evangelism and social action] is a means to the other...For each is an end in itself. Both are expressions of unfeigned love.

The apostle John has helped me to grasp this by these words from his first letter: 'If any one has the world's goods and sees his brother in need, yet closes his heart against him, how does God's love abide in him? Little children, let us not love in word or speech but in deed and in truth' (I John 3:17,18). Here love in action springs from a twofold situation, first 'seeing' a brother in need and secondly 'having' the wherewithal to meet the need. If I do not relate what I 'have' to what I 'see', I cannot claim to be indwelt by the love of God. Further, this principle applies whatever the nature of the seen need. I may see spiritual need (sin, guilt, lostness) and have the gospel knowledge to meet it. Or the need I see may be disease or ignorance or bad housing, and I may have the medical, educational, or social expertise to relieve it. To see need and to possess the remedy compels love to act, and whether the action will be evangelistic or social, or indeed polical, depends on what we 'see' and what we 'have'.

Of course, that does mean you always do just one or the other. But what I appreciate about this (as well as am challenged by!) is that Stott shows how "mission" doesn't exclude anyone, and if you have a job at the laundromat, you're not somehow less spiritual than a pastor who's involved in "full time ministry".