In 3:6 the writer has stated the need to “hold on to our courage and the hope of which we boast”. The word “courage” is more often translated “confidence” (eg. 4:16, 10:19, 35), and that meaning seems preferable here too. For this passage speaks of our hope (in terms of the rest that awaits us) and of the need to hold firm to our confidence without turning away in unbelief.
The passage might be better worked through as written in the study (and the two NIV headings give a good indication of the theme in each half), but let me try and unpack the meaning of the passage by considering the following questions –
The quotation from Psalm 95 mentions God speaking of “my rest”, but it is particularly in ch.4 that the meaning of this rest is explored. It is God’s rest because in the first place it refers back to the 7th day of creation (see 4:3b, 4), a rest that speaks not of a day off after a busy week but God’s enjoyment of all that he had made. It was a rest we were meant to share in as we enjoyed God’s many blessings and the wonderful world he had put us in, and enjoyed the wonder of knowing him. Since Genesis 3 we have no longer enjoyed that rest, the world has become a restless place.
The Promised Land was spoken of as the land of rest. So in Psalm 95 David is remembering the occasion in Numbers 13, 14, when the Israelites were poised to be led into the Land by Moses, and the people rebelled, refusing to go in, resulting in the punishment of 40 years wandering in the wilderness until that entire generation had died. None of them (except for Joshua and Caleb, who had trusted God’s promise), entered into the Promised Land.
And yet Canaan was only ever a picture/model of God’s rest – a prototype. God’s rest is not a piece of real estate in the Middle East, it is something much bigger and more wonderful. Hence, when David writes Ps.95 hundreds of years after Joshua had led the Israelites into the land, he implies we might still fail to enter God’s rest as that earlier generation had done if we don’t respond rightly to God’s Word. That’s the point being made in 4:6-9. The promise of remains (cf. 4:1), it is not something has been fulfilled under Joshua, it is still future, and therefore our situation is analogous to the Israelites before they entered the land.
The promise of rest comes to us in the Gospel (4:2). It is the same Gospel the Israelites had preached to them, though couched in different terms: remember Heb.1:1, the Gospel has now come into clearer and sharper focus in Jesus. What must our response be to God’s promise? Faith (4:2). Faith that “holds firmly to the end” (3:14). The example of the Israelites gives us a warning of what to avoid. Their disobedience was essentially unbelief – they hardened their hearts to God’s Word. The warning to us is given in 3:12: “See to it, brothers, that none of you has a sinful, unbelieving heart that turns away from the living God”, else we will prove that we are not those who have truly come to share in Christ (3:14).
We are to be very careful how we respond to God’s Word (cf.2:1), not hardening our hearts but believing it. The passage opens and closes with some important lessons about God’s Word. It is “living”, for the Holy Spirit addresses us today in the Scriptures. It is “active”, opening us up, exposing our hearts and the sin and unbelief that lurk there. But to ensure a right response to God’s Word we need each other too – daily encouragement (3:13). We have a responsibility for each other to ensure that none fall away (4:1,11). That is the reason for meeting as a Fellowship Group: to listen to God’s Word, and to encourage each other to heed it, to hold fast to it and to hold fast to Christ.