Another wile of Satan as a troubler, is in aggravating the saint’s sins, against which he hath a notable declamatory faculty— not that he hates sin, but the saint. Now in this, his chief subtlety is so to lay his charge, that it may seem to be the act of the Holy Spirit. He knows an arrow out of God’s quiver wounds deep; and therefore, when he accuseth, he comes in God’s name. As suppose a child were conscious to himself of displeasing his father, and one that owes him a spite, to trouble him, should counterfeit a letter from his father, and cunningly convey it into the son’s hand, who receives it as from his father. Therein he chargeth him with many heavy crimes, disowns him, and threatens he shall never come in his sight, or have penny portion from him; [and] the poor son, conscious to himself of many undutiful carriages, and not knowing the plot, takes on heavily, and can neither eat nor sleep from grief. Here is a real trouble begot from a false and imaginary ground. Thus Satan observes how the squares go between God and his children. Such a saint he sees tardy in his duty, faulty in that service, and he knows the Christian is conscious of this, and that the Spirit of God will also show his distaste for these; both which [reasons] prompt Satan to draw a charge at length, raking up all the aggravations he can think of, and give it into the saint as sent from God. Thus he taught Job’s friends to pick up those infirmities which dropped from him in his distress, and shoot them back in his face, as if indeed they had been sent from God to declare him an hypocrite, and denounce his wrath for the same. But how shall we know the false accusation of Satan from the rebukes of God and his Spirit?
1. If they cross any former act or work of the Spirit in thy soul, they are Satan’s, not the Holy Spirit’s. Now you shall observe Satan’s scope in accusing the Christian, and aggravating his sin, is to unsaint him, and persuade him he is but an hypocrite. Oh, saith Satan, now thou hast shown what thou art. See what a foul spot is on thy coat. This is not the spot of a child. Whoever, that was a saint, committed such a sin after such a sort? All thy comforts and confidence which thou hast bragged of, were false, I warrant you. Thus you see Satan at one blow dasheth all in pieces. The whole fabric of grace which God hath been rearing up many years in the soul, must now at one puff of his malicious mouth be blown down, and all the sweet comforts with which the Holy Spirit hath sealed up God’s love, must be defaced with this one blot, which Satan draws over the fair copy of the saint’s evidence. Well, soul, for thy comfort know, if ever the Spirit of God hath begun sanctifying or comforting work, causing thee to hope in his mercy, he never is, will, can be the messenger to bring contrary news to thy soul; His language is not yea and nay, but yea and amen for ever. Indeed, when the saint plays the wanton, he can chide, yea, will frown and tell the soul roundly of its sin, as he did David by Nathan. ‘Thou art the man’ —this thou hast done. He paints out his sin with such bloody colours, as made David’s heart melt, as it were, into so many drops of water. But that shall not serve his turn; he tells him what a rod is steeping for him, that shall smart to purpose— one of his own house, no other than his darling son, shall rise up against him. [This happens in order] that he may the more fully conceive how ill God took the sin of him, a child, a saint, when he shall know what it is to have his beloved child traitorously invade his crown, and unnaturally hunt for his precious life; yet not a word all this while is heard from Nathan teaching David to unsaint himself, and call in question the work ofGod in his soul. No, he had no such commission from God; he was sent to make him mourn for his sin, not from his sin to question his state which God had so oft put out of doubt.
2. When they asperse the riches of God’s grace, and so charge the Christian, that withal they reflect upon the good name of God, they are not of the Holy Spirit but from Satan. When you find your sins so represented and aggravated to you, as exceeding either the mercy of God’s nature, or the grace of his covenant, this comes from that foul liar. The Holy Spirit is Christ’s spokesman to commend him to souls, and to woo sinners to embrace the grace of the gospel; and can such words drop from his sacred lips, as should break the match and sink Christ’s esteem in the thoughts of the creature? You may know where this is mined. When you hear one commend another for a wise or good man, and at last come in with a but that dasheth all, you will easily think he is no friend to the man, but some sly enemy that by seeming to commend, desires to disgrace the more. Thus you find God represented to you as merciful and gracious, but not to such a great sinner as you. to have power and strength, but not able to save thee; you may say, Avaunt, Satan, thy speech betrayeth thee.
Source: http://www.puritanboard.com/f15/satans-work-accusation-how-does-work-83497/, Comment #2