The law is not of faith, so faith is not of the law. There is a faith indeed which the law requires and obliges to, namely, faith and trust in God, as the God of nature and providence; for as both the law of nature, and the law of Moses, show there is a God, and who is to be worshipped; they both require a belief of him, and trust and confidence in him; which is one part of the worship of him enjoined therein: moreover the law obliges men to give credit to any revelation of the mind and will of God he has made, or should think fit to make unto them at any time.
As is the revelation which is made to men, such is the faith which is required of them. If there is no revelation made unto them, no faith is required of them; and unbelief, or want of faith in Christ, will not be their damning sin, as is the case of the heathens; ‘for how shall they believe in Him of whom they have not heard? and how shall they hear without a preacher?’ No; they will be condemned not for their want of faith in Christ, or His Gospel, which they never heard of, but for their sins committed against the law and light of nature, ‘As many as have sinned without Law shall perish without Law’: if a revelation is made, this is either external or internal; if only an external revelation is made, the faith required is an assent unto it, and a reception of it; and such who do not attend to the evidence it brings with it, or reject and despise it, shall be damned: but if besides the external revelation, an internal revelation is made by the Spirit of Wisdom, in the knowledge of Christ; or if God by His Word calls men effectually by His Grace, and reveals His Son in them, as well as to them; this kind of revelation comes with such power and influence upon the mind, as certainly to produce a true and living faith in the soul, which infallibly issues in eternal life and happiness; and of such persons, and of such only, acts of special faith in Christ are required.
as for special faith in Christ as a Saviour, or believing in him to the saving of the soul; this the law knows nothing of, nor does it make it known; this kind of faith neither comes by the ministration of it, nor does it direct to Christ the object of it, nor give any encouragement to believe in him on the above account; but it is a blessing of the covenant of grace, which flows from electing love, is a gift of God's free grace, the operation of the Spirit of God, comes by the hearing of faith, or the word of faith, as a means, that is, the gospel; for which reason, among others, the gospel is so called; and it is that which points out Christ, the object of faith; and directs and encourages sensible sinners under a divine influence to exercise it on him; its language is, "believe on the Lord Jesus Christ, and thou shalt be saved", Ac 16:31".