We have come to share in Christ if we hold firmly to the end the assurance we had at first.
As it has been said:
“Today, if you hear His voice,
do not harden your hearts,
as you did in the rebellion.”
For who were the ones who heard and rebelled? Were they not all those Moses led out of Egypt?
And with whom was God angry for forty years? Was it not with those who sinned, whose bodies fell in the wilderness?
And to whom did He swear that they would never enter His rest? Was it not to those who disobeyed? So we see that it was because of their unbelief that they were unable to enter.
Essentially, we behave like Paul did before his transformation... we act like a zealot for the law and those who have a zeal for the law have a hard heart. Yes, the law was given to those Moses led out of Egypt to show them that the law was necessary so that they could see what they needed to become; God's own His chosen people. This was in preparation for the New Covenant and for His Kingdom.
Jesus Christ came into the world to fulfill the law that man could not nor ever measure up to let alone fulfill. Yet, we like Paul was...mistakenly think that we have to keep the law, uphold the law through the practice and preaching of the law. We have to bring justice, we have to make sure that everyone is doing what they are supposed to be doing according to the law... Wrong! We have a New Covenant with the Living God! Repent and harden NOT your heart!
This does not mean that we can now willingly break the law. It means we are no longer under condemnation of the law nor are we to condemn others. We are to forgive, to have mercy and compassion and to demonstrate that (to be salt and light) in order that souls are saved.