Q. 93. What is the moral law?
A. The moral law is the declaration of the will of God to mankind, directing and binding every one to personal, perfect, and perpetual conformity and obedience thereunto, in the frame and disposition of the whole man, soul and body,^[399] and in performance of all those duties of holiness and righteousness which he oweth to God and man:^[400] promising life upon the fulfilling, and threatening death upon the breach of it.^[401]

Q. 92. What did God at first reveal unto man as the rule of his obedience?
A. The rule of obedience revealed to Adam in the estate of innocence, and to all mankind in him, besides a special command not to eat of the fruit of the tree knowledge of good and evil, was the moral law.^[398]

Westminster Shorter Catechism

Q. 40. What did God at first reveal to man for the rule of his obedience?
A. The rule which God at first revealed to man for his obedience, was the moral law.^[114]

Chapter 19: Of the Law of God

1: God gave to Adam a law, as a covenant of works, by which He bound him and all his posterity, to personal, entire, exact, and perpetual obedience, promised life upon the fulfilling, and threatened death upon the breach of it, and endued him with power and ability to keep it.^[365]

Q. 91. What is the duty which God requireth of man?
A. The duty which God requireth of man, is obedience to his revealed will.^[397]

Westminster Shorter Catechism

Q. 39. What is the duty which God requireth of man?
A. The duty which God requireth of man, is obedience to his revealed will.^[113]

Chapter 18: Of Assurance of Grace and Salvation

4: True believers may have the assurance of their salvation divers ways shaken, diminished, and intermitted; as, by negligence in preserving of it, by falling into some special sin which wounds the conscience and grieves the Spirit; by some sudden or vehement temptation, by God’s withdrawing the light of His countenance, and suffering even such as fear Him to walk in darkness and to have no light:^[362] yet are they never so utterly destitute of that seed of God, and life of faith, that love of Christ and the brethren, that sincerity of heart, and conscience of duty, out of which, by the operation of the Spirit, this assurance may, in due time, be revived;^[363] and by the which, in the mean time, they are supported from utter despair.^[364]

Q. 81. Are all true believers at all times assured of their present being in the estate of grace, and that they shall be saved?
A. Assurance of grace and salvation not being of the essence of faith,^[353] true believers may wait long before they obtain it;^[354] and, after the enjoyment thereof, may have it weakened and intermitted, through manifold distempers, sins, temptations, and desertions;^[355] yet they are never left without such a presence and support of the Spirit of God as keeps them from sinking into utter despair.^[356]

Chapter 18: Of Assurance of Grace and Salvation

3: This infallible assurance does not so belong to the essence of faith, but that a true believer may wait long, and conflict with many difficulties, before he be partaker of it:^[357] yet, being enabled by the Spirit to know the things which are freely given him of God, he may, without extraordinary revelation in the right use of ordinary means, attain thereunto.^[358] And therefore it is the duty of every one to give all diligence to make his calling and election sure,^[359] that thereby his heart may be enlarged in peace and joy in the Holy Ghost, in love and thankfulness to God, and in strength and cheerfulness in the duties of obedience,^[360]the proper fruits of this assurance; so far is it from inclining men to looseness.^[361]

Chapter 18: Of Assurance of Grace and Salvation

2: This certainty is not a bare conjectural and probable persuasion grounded upon a fallible hope;^[352] but an infallible assurance of faith founded upon the divine truth of the promises of salvation,^[353] the inward evidence of those graces unto which these promises are made,^[354] the testimony of the Spirit of adoption witnessing with our spirits that we are the children of God,^[355] which Spirit is the earnest of our inheritance, whereby we are sealed to the day of redemption.^[356]

Q. 80. Can true believers be infallibly assured that they are in the estate of grace, and that they shall persevere therein unto salvation?
A. Such as truly believe in Christ, and endeavour to walk in all good conscience before him,^[349] may, without extraordinary revelation, by faith grounded upon the truth of God’s promises, and by the Spirit enabling them to discern in themselves those graces to which the promises of life are made,^[350] and bearing witness with their spirits that they are the children of God,^[351] be infallibly assured that they are in the estate of grace, and shall persevere therein unto salvation.^[352]

Chapter 18: Of Assurance of Grace and Salvation

1: Although hypocrites and other unregenerate men may vainly deceive themselves with false hopes and carnal presumptions of being in the favor of God, and estate of salvation^[348] (which hope of theirs shall perish):^[349] yet such as truly believe in the Lord Jesus, and love Him in sincerity, endeavouring to walk in all good conscience before Him, may, in this life, be certainly assured that they are in the state of grace,^[350] and may rejoice in the hope of the glory of God, which hope shall never make them ashamed.^[351]

Chapter 17: Of the Perseverance of the Saints

3: Nevertheless, they may, through the temptations of Satan and of the world, the prevalency of corruption remaining in them, and the neglect of the means of their preservation, fall into grievous sins;^[339] and, for a time, continue therein:^[340] whereby they incur God’s displeasure,^[341] and grieve His Holy Spirit,^[342] come to be deprived of some measure of their graces and comforts,^[343] have their hearts hardened,^[344] and their consciences wounded;^[345] hurt and scandalize others,^[346] and bring temporal judgments upon themselves.^[347]

Chapter 17: Of the Perseverance of the Saints

2: This perseverance of the saints depends not upon their own free will, but upon the immutability of the decree of election, flowing from the free and unchangeable love of God the Father;^[334] upon the efficacy of the merit and intercession of Jesus Christ,^[335] the abiding of the Spirit, and of the seed of God within them,^[336] and the nature of the covenant of grace:^[337] from all which arises also the certainty and infallibility thereof.^[338]

Q. 79. May not true believers, by reason of their imperfections, and the many temptations and sins they are overtaken with, fall away from the state of grace?
A. True believers, by reason of the unchangeable love of God,^[342] and his decree and covenant to give them perseverance,^[343] their inseparable union with Christ,^[344] his continual intercession for them,^[345] and the Spirit and seed of God abiding in them,^[346] can neither totally nor finally fall away from the state of grace,^[347] but are kept by the power of God through faith unto salvation.^[348]

Chapter 17: Of the Perseverance of the Saints

1: They, whom God has accepted in His Beloved, effectually called, and sanctified by His Spirit, can neither totally nor finally fall away from the state of grace, but shall certainly persevere therein to the end, and be eternally saved.^[333]