God does not take a break.
He works all the time.
We are not like that.
We need to rest.
But there is more than one kind of rest.
First, there is the rest we take when our work is done:
By the seventh day God had finished the work he had been doing; so on the seventh day, He rested from all His work.--Genesis 2:2
So, I nap on Sunday afternoon, right?
Maybe, but there is more.
The real rest God has for us is not just the break we take after digging a ditch or cooking a meal or building a house.
Our best work before God has less to do with our muscles than with our head and heart.
The real work God wants from us is to believe, and His rest is His reward.
"They are a people whose hearts go astray,
and they have not known my ways."
So I declared an oath in my anger,
"They shall never enter my rest."--Psalm 95:10-11
His rest is not a nap. His rest is the peace and luxury of His presence.
Like in this instance, when He denied the promised land to doubters and complainers, those of us who do not believe, who do not worship, will miss it.
God instructed the Israelites to rest on the first day of the week, so they made up a bunch of rules about walking and cooking, and that may still be necessary for workaholics. But He really wants us to have soft hearts before Him. That brings real rest.
So what are we to do on the seventh day?
We are to remember God, honor His ways, and worship Him, just like every day. But, because we have put aside our customary physical activities, we can pay special attention to Him while we do it.
Our Sunday activities are not defined by the kind of work we do as much as the One for Whom we do it. Our Sabbath is celebrated by special effort of belief, whatever that looks like.
How do I know this? Jesus said so:
The Sabbath was made for man, not man for the Sabbath.--Mark 2:27