Missing out on REST

 Hebrews 3:12 Take care, brothers, lest there be in any of you an evil, unbelieving heart, leading you to fall away from the living God. 13 But exhort one another every day, as long as it is called “today,” that none of you may be hardened by the deceitfulness of sin. 14 For we have come to share in Christ, if indeed we hold our original confidence firm to the end. 15 As it is said,
“Today, if you hear his voice,
do not harden your hearts as in the rebellion.”
16 For who were those who heard and yet rebelled? Was it not all those who left Egypt led by Moses? 17 And with whom was he provoked for forty years? Was it not with those who sinned, whose bodies fell in the wilderness? 18 And to whom did he swear that they would not enter his rest, but to those who were disobedient? 19 So we see that they were unable to enter because of unbelief.

This chapter opens with the writer comparing and contrasting Jesus with Moses.  Both were used by God to reveal His person and His plan, but Jesus was by far the greater revelation, being God's very Son.  With that being the case, rejection of His revelation would have even greater consequences. With all that the people of Israel had seen in the Exodus, they still rebelled against God, refusing to obey, and ended up dying in the wilderness wanderings. They did not enter the promised rest. How much more we will lose out on if we turn our backs on all God has revealed in Christ.