12 Beware, brothers, lest perhaps there be in any one of you an evil heart of unbelief, in falling away from the living God; 13 but exhort one another day by day, so long as it is called “today;” lest any one of you be hardened by the deceitfulness of sin. 14 For we have become partakers of Christ, if we hold fast the beginning of our confidence firm to the end: 15 while it is said,
“Today if you will hear his voice,
don’t harden your hearts, as in the rebellion.” [1] 16 For who, when they heard, rebelled? No, didn’t all those who came out of Egypt by Moses? 17 With whom was he displeased forty years? Wasn’t it with those who sinned, whose bodies fell in the wilderness? 18 To whom did he swear that they wouldn’t enter into his rest, but to those who were disobedient? 19 We see that they were not able to enter in because of unbelief.
Matthew Henry's Commentary on Hebrews 3:12-19
Commentary on Hebrews 3:7-13
(Read Hebrews 3:7-13)
Days of temptation are often days of provocation. But to provoke God, when he is letting us see that we entirely depend and live upon him, is a provocation indeed. The hardening of the heart is the spring of all other sins. The sins of others, especially of our relations, should be warnings to us. All sin, especially sin committed by God's professing, privileged people, not only provokes God, but it grieves him. God is loth to destroy any in, or for their sin; he waits long to be gracious to them. But sin, long persisted in, will make God's wrath discover itself in destroying the impenitent; there is no resting under the wrath of God. "Take heed:" all who would get safe to heaven must look about them; if once we allow ourselves to distrust God, we may soon desert him. Let those that think they stand, take heed lest they fall. Since to-morrow is not ours, we must make the best improvement of this day. And there are none, even the strongest of the flock, who do not need help of other Christians. Neither are there any so low and despised, but the care of their standing in the faith, and of their safety, belongs to all. Sin has so many ways and colours, that we need more eyes than ours own. Sin appears fair, but is vile; it appears pleasant, but is destructive; it promises much, but performs nothing. The deceitfulness of sin hardens the soul; one sin allowed makes way for another; and every act of sin confirms the habit. Let every one beware of sin.
Commentary on Hebrews 3:14-19
(Read Hebrews 3:14-19)
The saints' privilege is, they are made partakers of Christ, that is, of the Spirit, the nature, graces, righteousness, and life of Christ; they are interested in all Christ is, in all he has done, or will do. The same spirit with which Christians set out in the ways of God, they should maintain unto the end. Perseverance in faith is the best evidence of the sincerity of our faith. Hearing the word often is a means of salvation, yet, if not hearkened to, it will expose more to the Divine wrath. The happiness of being partakers of Christ and his complete salvation, and the fear of God's wrath and eternal misery, should stir us up to persevere in the life of obedient faith. Let us beware of trusting to outward privileges or professions, and pray to be numbered with the true believers who enter heaven, when all others fail because of unbelief. As our obedience follows according to the power of our faith, so our sins and want of care are according to the prevailing of unbelief in us.