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.
18. to them that believed not—rather as Greek, "to them that disobeyed." Practical unbelief (De 1:26).