Hebrews 4 The Israelites that had "hardened" their hearts.. failing to trust in God.. disobedient, obstinate and rebellious.. would not "enter" into God's "rest".  The writer wants us to understand what that rest is.. 

In verse 1 he warns us that we do not want to "come short" of that promised rest. 

In verse 2 he tells us that the Word is vital to entering that rest.. if "united by faith.. " 

In verse 3 he tells us that "we who have believed enter that rest.." 

In verse 4 he tells us that our rest is relative to the rest that God Himself entered on the 7th day. 

In verse 5 he reminds us once again that the unbelievers "shall not enter [His] rest."

In verse 6 he tells us that it is still possible to enter that rest.. if we are not disobedient like they were in the wilderness.

In verse 7 he tells us that there is a "certain day.. Today" that we are each given to "not harden [our] hearts".. but to "hear His voice"... so that we can enter His rest.

In verse 8 he tells us that Joshua did not give the people rest.. even though he led them into the promised land... but that there is "another day after that." 

In verse 9 he tells us that "there remains therefore a Sabbath of rest for the people of God."

In verse 10 he tells us that Jesus entered that rest himself .. resting from His works.. 

And in verse 11 he exhorts us to "be diligent to enter that rest, lest anyone fall through following the same example of disobedience." 

That is a lot of emphasis on "rest".   Followed by this, " For the word of God is living and active and sharper than any two-edged sword, and piercing as far as the division of soul and spirit, of both joints and marrow, able to judge the thoughts and intentions of the heart." 

The writer goes on to tell us that God sees "all things".. He sees into our souls and knows our hearts.  Everything is "open and laid bare to the eyes of Him with whom we have to do."  We must give an account before Him. We cannot hide our hardened hearts. We cannot pretend to be believers.  We must have Jesus.. our great High Priest.. or we will not enter into the eternal, glorious Kingdom of God's rest. 

Oh how marvelous is our High Priest!  He has "ascended into heaven." .  He is able to sympathize with our weaknesses.  He was tempted as we are.. yet He did not sin.  We must hold on "Firmly to the faith we profess."  And as we hold fast to Him we can "draw near with confidence to the throne of grace, that we may receive mercy, and may find grace to help in time of need." 

Father, thank You for such a High Priest as this.. Jesus, our Lord.  Help us to hold fast.. to not harden our hearts but to fully believe and trust in Him who has ascended to Your right Hand.  We yield to Your Spirit and draw near to Your throne of grace. We look forward to that day when we will be forever with You in that Holy Rest. Amen.