It's a case of tending everyone else's garden and not your own.
I have a bit of a problem with the short term (week or two) missions trips that so many groups enter into. I am not convinced of the value of these kinds of exercises. I think it's good to agree to a long term project like a soup kitchen or some such but to send people away to some far place to do short term ministry doesn't make sense to me.
To be honest our Son went off on such an expedition to Mexico. It was a worthwhile venture as an adventure. But, I'm not convinced of the value to the Mexicans.
The territory around a Christian might need serious tending (witness) , serious ministry, serious attention and yet we send people off somewhere at significant expense for what appears to my eyes to be letting weeds grow up in our own garden to go far away to weed someone else's.
That's the story in the Song of Solomon Chapter 1. The Shulamite has been send off by her brothers to take care of a vineyard she didn't own. Then her own vineyard was in bad repair. She was still lovely yet sunburned and not fair as women tried to be then. That's what we do, we send people off, they get burned and the garden they should have been tending to is lost.
5Dark am I, yet lovely, O daughters of Jerusalem, dark like the tents of Kedar, like the tent curtains of Solomon.
6 Do not stare at me because I am dark, because I am darkened by the sun. My mother's sons were angry with me and made me take care of the vineyards; my own vineyard I have neglected.
I'm not sure we always do well when we try to do good. We must be wise. Let's start by tending the vineyards of our own hearts, then our families, then our church, then our community and then.......
That's the biblical model. First Jerusalem. Uttermost parts can come a little later. Running helter skelter doesn't always get the weeds in our own garden pulled.