Canons of Dort, Head 5: Of the Perseverance of the Saints

Those whom God, according to His purpose, calls 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, though in this life He does not deliver them altogether from the body of sin and from the infirmities of the flesh. Yet by His Spirit He preserves them so that they cannot totally fall.