“You believe that God is one. You do well; the demons also believe, and shudder.”
“Judge, my friend, and let the reader judge, whether the meaning of the apostle be not expressed in the following paraphrase: Show me, if thou canst, a faith which is of any value without works, and I will show thee a faith which is of value by its fruits. Thou believest that there is one God; a great matter truly! and may not the same be said of the worst of beings? yea, and more: for they, having felt the power of God’s anger, not only believe, but tremble; whereas thy faith suffers thee to live at ease. But as theirs, with all their trembling, is of no account, neither is thine; for faith without holy fruits is dead.
“There is no reason to conclude that the faith and trembling of devils differ in any thing, except in degree, from the convictions and trembling of Felix: if, therefore, the former would in our circumstances have terminated in salvation, why did not the latter, whose situation was sufficiently favourable, so terminate? The convictions of James’s nominal Christian might not be so strong as those of Felix, and his might not be so strong as those of the fallen angels; in in their nature they were one and the same. The first was convinced that there was one God; but it was mere light without love. If, like what is said of the stony-ground hearers, a portion of joy at first attended it, yet, the gospel having no root in his mind, and being in circumstances wherein he saw no remarkable displays of the Divine majesty, it made no durable impression upon him. The second might also be convinced that there was a God, and neither were his convictions accompanied by love, but ‘righteousness, temperance, and a judgment to come,’ being set before him, he ‘trembled.’ The last are convinced of the same truth, and neither are their convictions accompanied by love; but being placed in circumstances wherein the awful majesty of God is continually before their eyes, they already know in part, but sad experience, the truth of his threatenings, and tremble in expectation of greater torments.” (Works, 266-267).
“We are taught to look upon a faith of bare speculation and knowledge [mere intellectual assent] as the faith of devils: Thou believest that there is one God; thou doest well; the devils also believe, and tremble, v. 19. That instance of faith which the apostle here chooses to mention is the first principle of all religion. “Thou believest that there is a God, against the atheists; and that there is but one God, against the idolaters; thou doest well: so far all is right. But to rest here, and take up a good opinion of thyself, or of thy state towards God, merely on account of thy believing in him, this will render thee miserable: The devils also believe, and tremble. If thou contentest thyself with a bare assent to articles of faith, and some speculations upon them, thus far the devils go. And as their faith and knowledge only serve to excite horror, so in a little time will thine.’ The word tremble is commonly looked upon as denoting a good effect of faith; but here it may rather be taken as a bad effect, when applied to the faith of devils. They tremble, not out of reverence, but hatred and opposition to that one God on whom they believe. To rehearse that article of our creed, therefore, I believe in God the Father Almighty, will not distinguish us from devils at last, unless we now give up ourselves to God as the gospel directs, and love him, and delight ourselves in him, and serve him, which the devils do not, cannot do.”
“Even fallen angels affirm the oneness of God and tremble at its implications. Demons are essentially orthodox in their doctrine (cf. Mt 8:29,30; Mk 5:7; Lk 4:41; Ac 19:15). But orthodox doctrine by itself is no proof of saving faith. they know the truth about God, Christ, and the Spirit, but hate it and Them.” (The MacArthur Study Bible footnote, NASB, p. 1899)
“He then who despises an acknowledged God is much worse.” (Commentaries, v. 22, p.313).
“The devils and damned souls have a great sense of the vast importance of the things of another world. They are in the invisible world, and they see and know how great the things of that world are. Their experience teaches them in the most affecting manner. They have a great sense of the worth of salvation and the worth of immortal souls and the vast importance of those things that concern men’s eternal welfare. The parable in the latter end of the sixteenth chapter of Luke teaches this in representing the rich man in hell as entreating that Lazarus might be sent to his five brothers to testify unto them, lest they should come to that place of torment. They who endure the torments of hell have doubtless a most lively and affecting sense of the vastness of an endless eternity and of the comparative momentariness of this life and of the vanity of the concerns and enjoyments of time. They are convinced, effectually, that all the things of this world, even those that appear greatest and most important to the inhabitants of the earth, are despicable trifles, in comparison to the things of the eternal world. They have a great sense of the preciousness of time and the means of grace and of the inestimable value of the privileges that they enjoy who live under the gospel. They are fully sensible of the folly of those that go on in sin, neglect their opportunities, make light of the counsels and warnings of God, and bitterly lament their exceeding folly in their own sins, by which they have brought on themselves so great and remediless misery. Therefore, however, true godliness is attended with a great sense of the importance of divine things, and it is rare that men who have no grace maintain such a sense in any steady and persevering manner, yet it is manifest those things are no certain evidences of grace.” (Sermon: True Grace Distinguished from the Experience of Devils)