I think this is a very important passage in regards to the seventh day. Do I understand it all? Hardly.
What is also important here is Hebrews 4:8-13.
Hebrews 4:8-13 (NIV)
8 For if Joshua had given them rest, God would not have spoken later about another day. 9 There remains, then, a Sabbath-rest for the people of God; 10 for anyone who enters God’s rest also rests from their works,[a] just as God did from his. 11 Let us, therefore, make every effort to enter that rest, so that no one will perish by following their example of disobedience.
12 For the word of God is alive and active. Sharper than any double-edged sword, it penetrates even to dividing soul and spirit, joints and marrow; it judges the thoughts and attitudes of the heart. 13 Nothing in all creation is hidden from God’s sight. Everything is uncovered and laid bare before the eyes of him to whom we must give account.
So here I am spit-balling.
We will never achieve rest by trying to earn heaven through our own works.
In this approach we will never enter God's rest.
If we place our faith in the finished work of God (Christ), and do not rely on our works, then we are now able to enter into God's rest. If we say we have faith but continue to be disobedient, ethen perhaps this is because we are still trying to find our rest through works and not through God. Thus why we will not enter God's rest.
Christ is our rest. Before Christ, the Sabbath was our rest.
We do not need the sabbath because Christ is now a better rest.
I still can't help but wonder, how can we enter God's rest if his day of rest has ended long ago? Unless of course we are still in the seventh day: the day of God's rest.