DT 9:6 “Know, then, it is not because of your righteousness that the LORD your God is giving you this good land to possess, for you are a stubborn people.
DT 9:7 “Remember, do not forget how you provoked the LORD your God to wrath in the wilderness; from the day that you left the land of Egypt until you arrived at this place, you have been rebellious against the LORD.
Israel must not mistake God's gift of the land as a reward for their righteousness. Their own history testified and cried out against them. They were not deserving recipients but a stubborn and rebellious people.
In the same way, the good land of salvation and eternal life is not given to us because of our righteousness for we have none. We must never think that we deserve His salvation because of something good in us. Oh no! Like Israel, our own history testifies against us. Our sins, our stubbornness, and our rebellion leave us with no grounds for boasting. We do not enter the land called salvation because we have been good but because God has been gracious.
Let me give a caveat here; a warning or a limiting explanation.
Some people interpret the Promise Land here as reaching heaven. Not so. As we read the Old Testament, in the Promise Land there were still struggles and battles that had to be fought. In heaven, we will no longer the church militant. There will be no more enemies to fight, no more battles to wage, and no more struggles against sin. Rather, in heaven we will be the church triumphant, enjoying the eternal victory of Christ.
Strictly, it is better to understand entering the Promise Land as the Christian Life here and now. I only made the promise land here as representing salvation for the purposes of evangelism.