Canaan was the land that the LORD had promised to Abraham's descendants. It was there that they would finally find peace and rest from the hands of their enemies but one thing was required - they had to believe God. During their wilderness wandering the people rebelled against the LORD. They murmured, complained and His anger flared towards them. He said:
Forty years long was I grieved with this generation, and said, It is a people that do err in their heart, and they have not known my ways: Unto whom I swore in my wrath that they should not enter into my rest. (Psalm 95:10-11)
All of that generation, except for Joshua and Caleb, died in the wilderness because of their unbelief. Joshua led the next generation into the Land of Promise but he was not be able to give them rest. Although they were standing in the promise, they did not have the faith that leads to rest; the faith that manifests in obedience. As such, they were exiled from the land.
The Promise of Rest
The Promised Land or Canaan was a picture of God's rest, not just for Israel but for all of mankind. God wanted to give Israel rest, not just from their physical labour and struggles of life, but also permanent rest in HIM that comes from the forgiveness of sin. That is God's heart for all of mankind but it requires faith in Yeshua Jesus. This faith is more that just saying "I believe in Jesus", because even demons believe and tremble (James 2:9). It is the type of faith that moves us action; namely obedience.
The Bible teaches us in the Prophetic Books that there is a time yet to come when all of Israel will find permanent rest in the Land of Canaan (now Israel) because God will forgive their sins, cleanse them and return them to their land. However, God's rest is available to everyone who desires it. The New Living Translation puts it this way:
God’s rest is there for people to enter, but those who first heard this good news failed to enter because they disobeyed God. So God set another time for entering his rest, and that time is today. God announced this through David much later in the words already quoted: “Today when you hear his voice, don’t harden your hearts.” Now if Joshua had succeeded in giving them this rest, God would not have spoken about another day of rest still to come. (Hebrews 4:6-7)
Today if you hear His voice, do not harden your heart - obey His voice and make every effort to enter into His rest!