The chapter begins by calling the readers holy brothers who share in a heavenly calling and asking them to consider Jesus, the apostle and high priest of their confession. Jesus was faithful to the one who appointed him, as Moses also was in all God's house. Yet Jesus is worthy of more glory, since the builder of a house has more honor than the house, and the builder of all things is God. Moses was faithful as a servant, to testify to what would be spoken later; Christ is faithful as a Son over God's house, and we are that house if we hold fast our confidence and the hope in which we boast.
For that reason the author quotes Psalm 95: if you hear his voice today, do not harden your hearts as in the rebellion, on the day of testing in the wilderness, where their fathers tested him for forty years. God was provoked with that generation, whose hearts went astray and who did not know his ways, and he swore that they would not enter his rest.
From that history the author draws a practical warning: take care that none of you has an evil, unbelieving heart that turns away from the living God. He urges them to encourage one another every day, as long as it is called today, so that none is hardened by the deceitfulness of sin, for they have come to share in Christ if they hold their original confidence firm to the end.
The chapter closes with rhetorical questions: who were those who heard and rebelled? Was it not all those who left Egypt under Moses? With whom was God provoked for forty years? Was it not those who sinned, whose bodies fell in the wilderness? And to whom did he swear that they would not enter his rest, if not those who were disobedient? The conclusion: we see that they were unable to enter because of unbelief.