THESIS I: Government in itself has been considered; its result follows, which concerns Angels or Men.
THESIS II: The result with respect to Angels was the obedience of some and their perseverance in the truth; that is, with goodness and integrity concreated: but the disobedience and defection of others from integrity.
THESIS III: Those that persevered in their integrity by the grace of God, are now so confirmed in it, that they are no longer able to fall from it: and they are called good Angels.
EXPLANATION: I. The truth and goodness, in which all Angels were created, but in which only some of all persevered, was, (1.) the illumination of the intellect, through which such an acquaintance with God and the divine works fell to them, as was necessary for the obtaining of the perfection of angelic nature and the end of their creation. (2.) The holiness of the will, or exact conformity with the law of God. And hence it is, that they are no longer able to fall and to sin: because neither their intellect nor their will is liable to error. Yet nothing is withdrawn from their liberty: because he is especially free, who is free from sin, in such a way that he is not able to be drawn into its servitude. See Exercitation 32.
II. The offices of the good Angels are: To praise God, and promptly to execute His commands, among which the principal concerns the defense of pious men against devils and impious men. Whence they are called λειτουργικὰ πνεύματα, that is, ministering spirits, sent forth to minister for them that shall be heirs of salvation, Hebrews 1:14. Scripture sets for their readiness to minister, when it says, that they stand before God. Daniel 7:10, before whom myriads of myriads were standing. Again, unto whom thousand thousands were ministering. Whence at the same time it is evident, that the multitude of good Angels is innumerable.
* III. It is proven, that Angels are no longer able to fall.
(1.) Because they always see the face of God the Father in heaven, Matthew 18:10. But the consummation of heavenly blessedness consists in that vision, John 17:24; 1 John 3:2; 1 Corinthians 13:12.
(2.) Because they are members of the Church triumphant, Revelation 21:12; Hebrews 12:22, 23.
(3.) Because they are elect, 1 Timothy 5:21.
(4.) Because we are going to be like unto them in the state of immutable glory, Matthew 22:30; Luke 20:36.
(5.) Because they are propounded to us as an example of perfect and constant obedience, Psalm 103:20.
(6.) Because Evil Angels are immutably evil and wretched.
THESIS IV: Those that persevered not in their integrity, through violation of the law given by God, with their intellect darkened, and their will turned by God, have become irreconcilable enemies of God and men: and are called evil Angels.
EXPLANATION: I. That some Angels revolted from God, and cast away their integrity and felicity, Scripture testifies. John 8:44, The Devil was a murderer from the beginning, and abode not in the truth. 2 Peter 2:4, If God spared not the Angles that sinned. Jude 6, Certain Angels are said not to have kept their first estate.
II. The efficient cause of this apostasy was the free will of the apostate Angels: for spontaneously, with no one compelling, they revolted from God, whether all at the same time, or with one soliciting the rest to apostasy. What drove them to defection from God and transgression of the divine law, Scripture does not teach: neither does it express their sin in particular, of what sort it was. It only says that they abode not in the truth, and they kept not their first estate. Their first sin is thought by Theologians to be pride: whence their envy towards God, and God’s image in man.
III. The effects or consequences of this apostasy were punishment, and the corruption accompanying punishment. The punishment was twofold: (1.) ejection from heaven into the lower parts of the earth, 2 Peter 2:4: (2.) eternal torments, Jude 6; Matthew 25:41.
The corruption accompanying the punishment is the hatred of God and of men. Whence the perpetual pursuit of striking at God and men, concerning which 1 Peter 5:8, Be sober; be vigilant: For your adversary the devil, as a roaring lion, walketh about, seeking whom he may devour. This corruption is indicated by names, the Devil, that is, the slanderer: because he calumniously and deceitfully traduces God before men, and men before God. Satan, that is, the adversary: because he, as an irreconcilable enemy, continually acts as an adversary to God and men. Πειράζων, that is, the tempter: because he continually solicits men to evil deeds. Ἐχθρὸς, that is, the enemy: because he is hostile to God, to Christ, and to mankind. Πονηρὸς, that is, the wicked one: because he himself is full of all wickedness, and in every way applies himself to the propagation of wickedness among men. Belial, that is, useless: because he willingly serves the interests of no one. Ἀπολλύων/Apollyon, that is, the ravager, destroyer,the great and ancient Dragon: because in ancient times, under the appearance of a serpent, he laid in wait for Eve, and poisoned her with his venom.
But, although by the fall the evil Angels were greatly corrupted, yet not obscure vestiges of the divine image remained in them, especially in their intellect and active power.
Knowledge, whether natural, or acquired and experimental, is not to be despised in them. Hence, by the application of hidden natural causes, which escape the notice of men, they are able to produce works, often marvelous in appearance, and also to predict future things, depending upon necessary natural causes, and to stir up tempests, with God permitting: even if by illusions they often baffle the sense and minds of men. Also, they have great acquaintance of the divine and human matters that are comprehended in things written, such that they are able to discourse concerning them with great subtlety: which is evident from the examples of those that by the help of familiar spirits sometimes make marvelous progress in letters and languages.
Yet this knowledge ought not to be extended to future contingencies, depending upon the free will of God and of man, or, as they vulgarly say, by chance: for God claims this prescience of events for Himself alone, Isaiah 41:23. Yet, if sometimes the event answer to the prediction of these also, it is to be thought to proceed either from a consideration of present causes, or from probable conjectures and comparison of similar things with similar.
Also, the power of evil Angels is still sufficiently great: yet it is not to be dreaded too much by the pious; because by the bridle of the divine power and wisdom it is restrained and guided, in such a way that they are not able to exert themselves, except where, when, and for how long God permits, to advance His glory and their salvation. Here, the history of Job is to be considered.
That the multitude of these malignant spirits is great, is evident from this, that sometimes an entire legion, which contains several thousands, might possess a single man: an example is found in Luke 8:30.
IV. Therefore, thus through Satan sin entered into the world: for he was the first to commit sin. Which in general is defined as vice, or a defect of the rational nature, opposing the divine law, and introducing a liability to eternal death. By the Apostle John it is defined in one word, ἀνομία/lawlessness, that is, vice opposing law, or violation of the law, 1 John 3:4: the consequent adjunct of which is guilt, or liability to just punishment.
Διαβολή/diabole signifies slander. שָׂטַן/satan signifies to act as an adversary.  Matthew 4:3: “And when the tempter (ὁ πειράζων) came to him, he said, If thou be the Son of God, command that these stones be made bread.” 1 Thessalonians 3:5: “For this cause, when I could no longer forbear, I sent to know your faith, lest by some means the tempter have tempted you (μήπως ἐπείρασεν ὑμᾶς ὁ πειράζων), and our labour be in vain.”  Matthew 13:39: “The enemy (ὁ δὲ ἐχθρὸς) that sowed them is the devil; the harvest is the end of the world; and the reapers are the angels.” Luke 10:19: “Behold, I give unto you power to tread on serpents and scorpions, and over all the power of the enemy (τοῦ ἐχθροῦ): and nothing shall by any means hurt you.”  Matthew 13:19: “When any one heareth the word of the kingdom, and understandeth it not, then cometh the wicked one (ὁ πονηρός), and catcheth away that which was sown in his heart. This is he which received seed by the way side.” 1 John 3:12: “Not as Cain, who was of that wicked one (τοῦ πονηροῦ), and slew his brother. And wherefore slew he him? Because his own works were evil, and his brother’s righteous.”  Revelation 9:11. Ἀπόλλυμι signifies to destroy.  Revelation 12:9.  See Job 1:19.  1 John 3:4: “Whosoever committeth sin transgresseth also the law: for sin is the transgression of the law (πᾶς ὁ ποιῶν τὴν ἁμαρτίαν, καὶ τὴν ἀνομίαν ποιεῖ· καὶ ἡ ἁμαρτία ἐστὶν ἡ ἀνομία).”