Drawing a connection between ourselves and the Israelites whom Joshua led into the wilderness is perhaps a bit difficult given the various gaps that lie between us. This same issue, though perhaps minimized to some degree, exists for a comparison between the original readership of the epistle to the Hebrews and those who entered into Canaan. Still, there are at least two principal relationships that we are to consider between ourselves and those whom God, through Moses, led out of Egypt to enter into His promised land, through Joshua. First, just as Paul exhorts the 1st century church at Corinth that many of the events from Egypt to the wilderness "happened as examples for us, so that we would not crave evil things as they also craved [...], and they were written for our instruction, upon whom the ends of the ages have come" (1 Corinthians 10:6, 11). Hebrews repeatedly encourages us to learn from those who fell in the wilderness, so that we do not "fall, through following the same example of disobedience" (Hebrews 4:11; see also 3:6-19; 4:1, 6-7). Second, though we live in a different place at a different time, and though many if not most of us are in no way connected to the Israelites of old in a physical sense, there is much that can (and does) wed us to those who did enter God's rest. As much of Hebrews argues, it is not the temporal or spatial/geographical or ethnic aspects that unite us, but rather faith (4:2; 10:39-11:40) and belief in (4:3), and obedience to the call of God through the Holy Spirit (3:6-11; 4:6-11). And, most importantly, since Joshua (Greek, Iesous, or "Jesus") did not (and could not) truly grant the fulness of God's rest, we are united across space and time to those who "have come to Mt. Zion"(12:22) and "to God [Himself]" (12:23) through the true Jesus "who has passed through the heavens" (4:14), granting us eternal rest in the presence of God, predicated on Christ's Person and work.
Yet, though entering in God's "rest" in Hebrews 4 entails cessation from work, rooted in the rest that God instantiated when He ceased His initial creation, we are nevertheless neither expected nor encouraged to do nothing, even though "we who have believed enter into that rest" (4:3, emphasis added). Rather than being motivated toward inaction, we are compelled to action as we are transformed by the power of God, through the indwelling of the Holy Spirit, into the image and likeness of Jesus Christ, the only begotten Son of God. The rest of God may very well be cessation from works, but it is not the absence of action. The rest of God to which we enter in through Jesus Christ is a dynamic relationship of active participation of love and adoration of the Triune Godhead, whom we worship in both this present world and the world without end. And this occurs by God's direct invitation, who has called to participate in the rest of Himself by initiating a relationship with humankind through the God-man Jesus Christ, of whom the "Jesus" of old (i.e., Joshua) was but a type. So, just as Jesus, the Son of God, is greater than the angels (Hebrews 1 & 2), and just as He is greater than Moses (Hebrews 3), so He is greater than Joshua. Therefore, Jesus alone is the "door" through which we enter into God's rest; He alone is "the way" to the Father (John 10:9). And, Jesus alone earned this entry on our behalf through His incarnation, life, death, resurrection, and ascension into heaven. For this reason, faith, belief, and obedience in Jesus Christ are paramount in establishing a lasting relationship that transcends space, time, and ethnicity in order to unite the people of God who enter His rest through the Son.
Moreover, the dynamic, participatory elements of God's rest illuminate the seeming paradox wherein we are called to "be diligent to enter that rest" (Hebrews 4:11). This exhortation appears paradoxical for at least two reasons. First, how can we enter into something to which we have already entered in (see 4:3)? Second, how can we "be diligent" or "labour" (4:11, KJV) to enter rest that has already been won/established on our behalf? Both of these relate to the the "already/not-yet" tension that we discussed in a previous post, and they also pertain to the very nature of the rest itself, mentioned above. That is, Christ, through His own eternal merits, has labored and earned for us the ability to enter God's rest. Furthermore, we experience that rest now by believing in Christ and being found in Him. Still, we "await" Christ and the "salvation" that He will usher in at His second coming (9:28, NASB). It is at this time when the life of the world to come will be realized in all of its eternal glory, filled with the "light" of the "Lord God," when we "put on immortality" and "imperishable[ness]" and are "made alive" with Christ at His "coming" (Revelation 22:5; 1 Corinthians 15:22-23, 51-53). In that interim, that is, until "we see Him just as He is" (1 John 3:2) and God "reign[s] forever and ever" (Exodus 15:18; Revelation 11:15; 22:5), we are encouraged to "be diligent to enter into that rest" (Hebrews 4:11). Our ability to do so is not even truly ours, as it is God who work in us "both to will and to work for His good pleasure" (Philippians 2:13). But, that we must do so is evident, "so that no one will fall, through following the same example of disobedience" as did the unbelievers in the wilderness (Hebrews 4:11).
The key then, to "be[ing] diligent to enter [God's] rest," is to not only hear the words of God, but to have His words "united by faith in those who heard" (4:2). Rather than exhibiting "unbelief" (3:12, 19) and being "disobedient" (3:18; 4:6, 11), we are called to believe, and to obey in love. And, as we "labour [...] to enter into that rest" (4:11, KJV), let us be ever mindful that we are "protected by the power of God through faith for a salvation ready to be revealed in the last time" (1 Peter 1:5, NASB). Jesus did not "lose" any of His disciples (John 18:9), and He will not lose us "who are called according to His purpose" (Romans 8:28). For, we give glory to God the Father,
who has blessed us with every spiritual blessing in the heavenly places in Christ, just as He chose us in Him before the foundation of the world, that we would be holy and blameless before Him. In love He predestined us to adoption as sons through Jesus Christ to Himself, according to the kind intention of His will, to the praise and glory of His grace, which He freely bestowed on us in the Beloved." (Ephesians 1:3-6)
We are confident to labor in order to enter into the rest of God, for we know that God, who began the "good work" in us, will "perfect it until the day of Christ Jesus" (Philippians 1:6). We who believe in Him and His words are assured entry because of the glorious Person and work of the true Jesus (see Hebrews 4:8). We know that we await the "Sabbath rest" of God, for "His works were finished" at the very moment when "He chose us in Him": "the foundation of the world" (Hebrews 4:3; Ephesians 1:4).