Heb. 4:11 ... "Let us be diligent to enter that rest, so that no one will fall, through following the same example of disobedience."
Looking backward into the Old Testament scriptures with their record of God's activity among Israel and the people's response thereunto, Paul wrote in I Cor. 10:11, "These things happened to them as an example, and they were written for our instruction." One of the most decisive and memorable of those occasions involved the experience of the Hebrews led by Moses out of Egypt and across the desolate wastes of Sinai to the threshhold of Canaan. God had promised to give that land to them as a rest from their bondage in an alien land, but the fulfillment of that promise was contingent upon their faith to follow God's directions. When the time came to exercise their faith by invading Canaan from the south, attacking fortified cities, and battling trained soldiers who were of greater stature than they, the hearts of the people melted within them. In the fear generated by a very weak faith, they rebelled and turned back into the relative safety of the desert. God's response was to abandon them to that desert until it swallowed every one of them except Joshua and Caleb, the two spies who had encouraged the people to follow God's lead in attacking Canaan. Out of the hundreds of thousands in that generation only those two men were finally allowed to enter Canaan as decisive conquerors, to take possession of it and enjoy the rest there that God had intended for all of them.
God's promise of a rest for His people was not abrogated by the abysmal failure of the Israelites. The generation that followed was led triumphantly into Canaan by Joshua and given to them for their possession. In vs. 8-9 it states that "if Joshua had given them rest, He would not have spoken of another day after that. So there remains a Sabbath rest for the people of God." God has promised another rest to His people of the Christian Age, only this rest is heavenly rather than earthly, spiritual rather than material, and eternal rather than temporal. Just as it was in the case of the Israelites, it is contingent upon our faith to yield our lives to His direction and to perform the works of spiritual service for which He has created us in His Son, (Eph. 2:10). If we ignore His will, revealed to us in the New Testament, then we will, like that faithless generation so long ago, "fall, through following the same example of disobedience." We can then be sure we will not "enter that rest."
Christians always face the danger of becoming complacent, taking the grace of God for granted, and participating less and less in the "good works, which God prepared beforehand so that we would walk in them," (Eph. 2:10). If we do not wear ourselves out in God's service, we have no need for any rest in the life beyond. It is the one who has worked through the day, endured the heat of the sun, and produced fruit by the sweat of his brow, who needs and deserves the bliss of sweet rest at the end of the day. Through the apostle John the Lord wrote to the Christians at Ephesus, "Remember from where you have fallen, and repent and do the deeds you did at first, or else I am coming to you and will remove your lampstand out of its place --- unless you repent," (Rev. 2:5). These people were obviously on the verge of missing "that rest" because they had ceased to "be diligent to enter" it. Perhaps their attention had been diverted by other activities in which they were engaging, or perhaps they were resting on the laurels of past achievements, or perhaps they had settled into the practice of just "keeping house for the Lord," the fault of many modern congregations. Whatever their situation, they were not busily and zealously involved in the works required by the gospel. It is sobering to consider Jesus' description of the Final Judgment in Mat. 25:31-46, where those who were assembled on His left hand were excluded from the rest of heaven because they had not been active in evangelism, edification, and benevolence for Jesus' sake while they yet lived on earth.
