I recall reading this passage about 20 years ago and realizing that it meant that Christians entered a different kind of Sabbath, one which is not one day in seven, but a lifetime of freedom from striving, similar to what Dan_473 added. I knew at the time that I didn't fully get it, but that I had deeply scratched the surface and had sensed the truth the passage was stating.
In Hebrews 4:11, it says, "Let us, therefore, make every effort to enter that rest..." This suggests that it is not just absence of effort which gets us 'in'. Rather, there is specific work to be done: "so that no one will fall by following
their example of disobedience." The "work" is obedience to the method God prescribes: we enter by faith, which is what the Israelites lacked (v.2). This sounds convoluted, and I'm not certain I have it all together yet.
The quotation of Psalm 95 in Hebrews 3 gives more context. The Israelites saw God's handiwork daily over the course of 40 years in the desert, yet still they did not believe and trust Him. If witnessing miracles constantly is not enough to convince people, what is? It is little wonder then that Jesus says to Thomas, "Blessed are those who have not seen and yet believe" (John 20:29). The Israelites could only see as far as the
last miracle. They repeatedly tested and tried God, demanding signs and miracles rather than resting in the confidence of His proven character.
So what does this mean for us? We need to see beyond what is written, what is already experienced in our own lives and the lives of others, and extrapolate that experience by faith, seeing God as unchangingly faithful, provisional, powerful, and good, that He is the same tomorrow as He was yesterday, and that where He states something, it is as certain as sunset and sunrise.
What does this all have to do with rest? Perhaps consider a child on a long car ride... "Are we there yet?" No, but we will get there. The adult "rests" in the adequate certainty that the destination will be reached in time. So too I think our relationship with God is restful in the sense that we are certain of His promises to us, that we don't need to strive constantly to ensure our worrying hearts of the reality and certainty of Who God is by needing new 'proof'. Jesus Christ is all the proof we
really need.
But, these are just
my thoughts.