This passage can be divided into three clean parts. The first is a further development of the idea of rest. God rested. Jesus rested. We must rest, too. Labor, he says, to enter into that rest (Hebrews 4:11). Faith takes work. Either you believe and res or harden your heart and experience judgment.
The second part shows the means for entering God's rest -- His word. God's word is the hinge between judgment and rest. I love and hate that it is so penetrating. God's word is his surgical instrument to examine me and to do surgery on me!
The third section deals with Jesus as the perfect high priest. We are invited, because Jesus is such a perfect pries, to come boldly into the throne room of God to find grace to help just-in-time. Jesus sympathy, his similar testing, and his sinlessness qualify him perfectly to represent us!