Parallelism suggests a connection of meaning through an echo of form.
During the wilderness wanderings of the Hebrews who had been led from Egyptian bondage, at the behest of God through Moses, they went directly to the Promised Land, (Canaan). But when they refused to enter the land of Canaan due to their disobedience which showed itself through their flagrant refusal to follow God's instructions to save themselves and to enter into His rest, they were mirroring a future event that would replay itself over and over throughout history, millions of times.
Because they didn't trust God's instructions, the adults of that generation all died in the desert. They had a choice. They shouldn't have died there.
Today, millions of people, though they know the truth of salvation through Christ, refuse to follow Him and thus they will die in the desert of unbelief. Instead of entering the "promised land" of Heaven, they will enter the desert of hell by their own choice and by their refusal to simply receive the gift of eternal life Jesus has already purchased for them by His death on the cross.
Have you made the choice to follow Jesus into the land of rest? or have you decided not to trust Him for that rest. Let me urge you right now to trust Him. Hebrews 3:15 says it clearly... (3:7-8), "Today, if you will hear His voice, do not harden your hearts as you did in the rebellion, during the time of testing in the wilderness." You see, there is still time for you. If you haven't given your heart and life to Jesus, trust Him now, then when you come to the final day, you will enter into His rest instead of the unmitigated wilderness and desert of hell.