Of the perseverance of the saints
The Canons of DortChapter 5, Articles 1, 2, 6, and 8Whom God calls, according to His purpose, to the communion of His Son, our Lord Jesus Christ, and regenerates by the Holy Spirit, He delivers also from the dominion and slavery of sin in this life; though not altogether from the body of sin and from the infirmities of the flesh, so long as they continue in this world.
Hence spring daily sins of infirmity, and hence spots adhere to the best works of the saints, which furnish them with constant matter for humiliation before God, and flying for refuge to Christ crucified; for mortifying the flesh more and more by the spirit of prayer, and by holy exercises of piety; and for pressing forward to the goal of perfection, till being at length delivered from this body of death, they are brought to reign with the Lamb of God in heaven.
God, who is rich in mercy, according to His unchangeable purpose of election, does not wholly withdraw the Holy Spirit from His own people, even in their melancholy falls; nor suffers them to proceed so far as to lose the grace of adoption, and forfeit the state of justification, or to commit the sin unto death; nor does He permit them to be totally deserted, and to plunge themselves into everlasting destruction.
Thus, it is not in consequence of their own merits or strength, but of God’s free mercy, that they do not totally fall from faith and grace, nor continue and perish finally in their backslidings; which, with respect to themselves, is not only possible, but would undoubtedly happen; but with respect to God, it is utterly impossible, since His counsel cannot be changed nor His promise fail, neither can the call according to His purpose be revoked, nor the merit, intercession and preservation of Christ be rendered ineffectual, nor the sealing of the Holy Spirit be frustrated or obliterated.

