Hebrews 3:7-19 - A Serious Warning Against Unbelief

⁷ Therefore, just as the Holy Spirit says, "Today, if you hear his voice, ⁸ do not harden your hearts as in the rebellion, in the day of testing in the wilderness, ⁹ where your fathers tested [me] by trial and saw my works ¹⁰ [for] forty years. Therefore I was angry with this generation, and I said, 'They always go astray in their heart, and they do not know my ways.' ¹¹ As I swore in my anger, '{They will never enter} into my rest.'"

¹² Watch out, brothers, lest there be in some of you an evil, unbelieving heart, [with the result that you] fall away from the living God. ¹³ But encourage one another {day by day}, as long as it is called "today," so that {none of you become hardened} by the deception of sin. ¹⁴ For we have become partners of Christ, if indeed we hold fast the beginning of [our] commitment steadfast until the end, ¹⁵ {while it is said}, "Today, if you hear his voice, do not harden your hearts as in the rebellion."

¹⁶ For who, [when they] heard [it], were disobedient? Surely [it was] not all who went out from Egypt through Moses? ¹⁷ And with whom was he angry [for] forty years? [Was it] not with those who sinned, whose dead bodies fell in the wilderness? ¹⁸ And to whom did he swear [they would] not enter into his rest, except those who were disobedient? ¹⁹ And [so] we see that they were not able to enter because of unbelief.