Over the past number of weeks, I've been learning so much about what it means to keep Sabbath. I was first taught about this concept as a child, by my parents. Sundays were the day of the week when we didn't do any shopping, when we didn't go out to restaurants, when we went to church, and when we had Sunday naps—at least, they did.
(On Sundays, Mum would precariously lean laundry hampers against our closed bedroom doors to alert her with a thump if we left our rooms. We would fashion bodies out of stuffed animals, with tufts of doll hair the same colour as our own sticking out from the top edges of the covers; contort ourselves around the laundry hamper alarm systems; and still get out to play.)
I've taken the concept of Sabbath into adulthood. Not quite with the same rigidity—we do allow ourselves to go out to eat, or pick up a few groceries—but the concept of setting aside one day a week has always been there.
And yet, I've been realizing over the last little while that up until very recently I've been doing it all wrong.
The idea of Sabbath is not synonymous with leisure. Sabbath is rest, but it's intentional. It doesn't fritter away the hours in frivolous ventures. We keep Sabbath, not by going our own way, but by finding our joy in the Lord. 
"Sabbath is preparedness training of sorts.… keeping it [nurtures] something deep and hidden that [comes] to light only on the day of testing." 
Unlike sleep, Sabbath rest respects our choices. It will not impose itself upon us if we wilfully ignore it. And yet, if we do, we suffer for it, with being too tired after work, unrefreshed by vacation, and unreliable to our friends. Though Sabbath gives us a choice, our choices do still yield consequences.
Those of us who are in people-centred vocations especially need this recognition. Without Sabbath, "we become the prey rather than a hunter."  Our insides are eaten out, our purpose becomes twisted, and our God begins to shrink.
We begin to think that everything depends on us, and that if we step away from our work, everything will fall apart.
But Colossians 3:17 says, "[Jesus] is before all things, and in Him all things hold together."
It is only God who holds all things together, and when we mistakenly embrace the idea that everything will fall apart if we aren't actively holding our lives and ministries together, we equate ourselves with God.
Violating Sabbath rest means that we inflate our own sense of self-importance and diminish the power of God.
Of course, when we rest, we feel vulnerable. This is just as true for sleep as it is for keeping the Sabbath—and it may be why we're so often tempted to ignore the Sabbath. We shy away from our own vulnerability, and prop up the illusion that we are in control of everything.
But the reality is:
"Either God is good and in control, or it all depends on [us]." 
As I wrote to a friend the other day:
During this time when God has called Peter and me apart, I keep having to push back against my own desire to please people, and to remind myself that God is the only one I really need to please. So it actually took quite a lot of courage for me to share in our newsletter about the rest that we're getting now, because I feel anxious about how it might be perceived.
That being said, I do think it's important to push back against our "missionaries ought to kill themselves for the sake of the Gospel" mentality, because I do think that it can lead to an idolatry of overwork. And also to too much reliance on our own efforts, and not enough on God's.
Just like sleep, "real Sabbath, the kind that empties and fills us, depends on… complete confidence and trust." 
This brings me back to the idea that Sabbath is preparedness training. The patterns that we apply in Sabbath rest build the foundation for our ministry. If we cower before the opinions of men in our rest, we will cower before those same men when courage is required in our ministry. If we trust God with our rest, it's easier for us to trust God with our ministries.
If we allow our ministries to be built on our own efforts, there can be no success. There can be no result of lasting and eternal value. "Unless the Lord builds the house, the builders labour in vain." 
How glad I am that we have never been called to do this work in our own strength. The Lord is the One who provides the work, who provides the soil and seed, and who provides the strength.
"So neither he who plants nor he who waters is anything, but only God who gives the growth." (1 Corinthians 3:7, ESV)
 See Isaiah 58:13–14.
 Mark Buchanan, The Rest of God (Nashville, TN: Thomas Nelson, 2006), 185–186 of 644 in ebook.
 Wayne Cordeiro, Leading on Empty (Bloomington, MN: Bethany House Publishers, 2009), 79 of 570 in ebook.
 Mark Buchanan, The Rest of God (Nashville, TN: Thomas Nelson, 2006), 196 of 644 in ebook.
 Ibid, 195 of 644 in ebook.
 Psalm 127:1, NIV.