Hebrews 3:7-19 - A Serious Warning Against Unbelief
7 Therefore, as the Holy Spirit says: "Today, if you will hear his voice, 8 do not harden your hearts as in the rebellion, on the day of testing in the wilderness, 9 where your fathers put me to the test and saw my works for forty years. 10 Therefore I was angry with that generation, and said, 'They always go astray in their hearts; and they have not known my ways.' 11 As I swore in my wrath, 'They shall never enter my rest.'"
12 Take care, brethren, lest there be in any one 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," so that none of you may be hardened by the deceitfulness of sin. 14 For we have come to share in Christ if we hold our first confidence firm to the end, 15 while it is said, "Today, if you will hear his voice, do not harden your hearts as in the rebellion."
16 Who were they who heard and rebelled? Were they not all those Moses led out of Egypt? 17 And with whom was he angry 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 never enter his rest, but to those who were disobedient? 19 So we see that they were not able to enter because of unbelief.