I recently listened to this message by John Piper about the task of world missions. Yes, it’s more than an hour long, but I still recommend it as being worth your time. The transcript is also available, so you could read it instead if you prefer. I listened to it while I was working in the kitchen.
When there are so many needs and causes pressing in on us, and people asking for our time and resources, we need clarity and vision to know where our limited resources should be going. Listening to this message helped do that for me.