"There remains a rest for the people of God. For he that has entered into his rest, he also has ceased from his own works as God did from his" Hebrews 4:9-10.
There are many that are trying to work their way into heaven by their works and their obedience to the law. They have not entered into his rest. No one will see heaven that has not entered into God's rest. What is this rest? The rest is the Gospel. In the Gospel Jesus defeats sin, death and the devil and throws open the gates of heaven so that whosoever will, may go in. Romans 10:13.
Those that believe the Gospel have ceased from their own works and obedience to the law and are resting in the righteousness and the obedience of Jesus Christ for their salvation. If you are a religious person this will not make sense to you. You have been taught that you must, you must, you must, or you will be anathema. Paul is saying... "stop working and enter into his rest".
There is an analogy concerning Hebrews 4:9-10. God commanded the Israelites to go in and possess the land that was promised to them. They had been wandering in the wilderness for over 40 years and now it was time to enter the promised land. But as usual, the Jews refused to obey God. God told them that he would help them to possess the land. They didn't believe him. "So, we see that they could not enter in because of unbelief" Hebrews 3:19. They finally did enter in, but only after God threatened to destroy them.
Paul wrote, "For unto us was the Gospel preached, as well as unto them (the Jews) but the word preached did not profit ithem, not being mixed with faith in them that heard it" Hebrews 4:2. We enter into Christ's rest by hearing and believing the Gospel. But if you don't believe the Gospel you cannot enter into his rest. In the Gospel Jesus has done it all and he did it perfectly. We rest in his righteousness and in his atonement for our sins.
In Matthew 7:21-23, Jesus said that only those who do the will of the Father will enter the Kingdom of Heaven and that he will tell those who are workers of lawlessness to depart from him because he never knew them, so choosing to obey God 's law required to enter Heaven, but not in order to work our way into heaven. Furthermore, in Hebrews is does not list the reason that they failed to enter into God's rest as being that they were trying to work their way to heaven, but rather Hebrews 3:18-19 says that they didn't enter God's rest because of their unbelief/disobedience. Furthermore, in Hebrews 4:11, we should strive to enter into God's rest so that no one may fall away by the same sort of disobedience.
Likewise, Romans 10:5-10, our faith references Deuteronomy 30:11-16 in regard to saying that God's law is not too difficult for us to obey, that the one who obeyed it will attain life by it, in regard to what we are agreeing to obey when we confess that Jesus is Lord, in in regard to the way to believe that God raised him from the dead. Furthermore, Romans 10:16 speaks against those who do not obey the Gospel. Nowhere did Paul say that and enter God's rest, but rather you are deliberately ignoring that he said the opposite. In Matthew 4:17-23, Jesus began his ministry with the Gospel message to repent for the Kingdom of God is at hand, and God's law is how his audience knew what sin is, so repenting from our disobedience to it is an integral part of the Gospel message, which you are again deliberately rejecting.