In his book Precious Remedies Against Satan's Devices, Thomas Brooks reminds believers that Satan must have permission from God and permission from the believer himself before Satan can do anything against the believer's happiness:
"Satan has only a persuading sleight, not an enforcing might. He may tempt us -- but without ourselves he cannot conquer us; he may entice us -- but without ourselves he cannot hurt us. Our hearts carry the greatest guilt in every sin. Satan can never undo a man without himself...And as Satan must have permission from God, so he must have permission from us. When he tempts us, we must assent; when he makes offers, we must hearken; when he commands, we must obey, or else all his labor and temptations will be frustrated, and the evil that he tempts us to shall be put down only to his account" (Kindle location 3281-3307).
Next he encourages believers to resist temptation:
"Make strong and constant resistance against Satan's temptations. Make resistance against temptations by arguments drawn from the honor of God, the love of God, your union and communion with God; and from the blood of Christ, the death of Christ, and the glory of Christ; and from the voice of the Spirit, the counsel of the Spirit, the comforts of the Spirit, the presence of the Spirit, the seal of the Spirit, the whisperings of the Spirit, the commands of the Spirit, the assistance of the Spirit, the witness of the Spirit; and from the glory of heaven, the excellency of grace, the beauty of holiness, the worth of the soul, and the vile or bitterness and evil of sin -- the least sin being a greater evil than the greatest temptation in the world.
And see that you make constant resistance, as well as strong resistance. Satan will come on with new temptations when old ones are weak...When you have overcome one temptation, you must be ready to enter the battle with another.
...remember, that it is dangerous to yield to the least sin -- to be rid of the greatest temptation. To take this course were as if a man should think to wash himself clean in ink, or as if a man should exchange a light cross, made of paper, for an iron cross, which is heavy, toilsome, and bloody. The least sin set home upon the conscience, will more wound, vex, and oppress the soul, than all the temptations in the world can...He who will yield to sin to be rid of temptation, will be so much the more tempted -- and the less able to withstand temptations," (Kindle locations 2519-2537).
Then Mr. Brooks continues to teach believers how to fight Satan:
"He who fights against Satan, in the strength of his own resolutions, constitution or education, will certainly fly and fall before him. Satan will be too hard for such a soul, and lead him captive at his pleasure...If ever you would be too hard for Satan, and after all his assaults, have your bow abide in strength, then take to yourself the Word of God, which is 'the two-edged sword of the Spirit, and the shield of faith, whereby you shall be able to quench all the fiery darts of the devil' (Eph. 6:17)," (Kindle location 3328, 3347).
He warns believers to keep watch:
"...If you would not be taken in any of Satan's snares, then keep a strong, close, and constant watch (1 Thess. 5:6). A sleepy soul that will not watch against temptations, will certainly fall before the power of temptations. Satan works most strongly on the imagination, when the soul is drowsy...Watchfulness includes a waking, a rousing up of the soul. It is a continual, careful observing of our hearts and ways, in all the turning of our lives -- that we still keep close to God and his Word...Watchfulness is the heart busied and employed with diligent observation of what comes from within us, and of what comes from without us and into us," (Kindle location 3446-3455).
Finally, he exhorts believers to remember:
"A soul high in communion with God may be tempted -- but will not be easily conquered...Communion with God is very inflaming, elevating and strengthening...If you would not be taken in any of Satan's snares, then do not engage Satan in your own strength -- but be every day drawing new virtue and strength from the Lord Jesus. Certainly that soul that engages against any old or new temptation without new strength, new influences from on high -- will fall before the power of the temptation.
...Ah, souls! remember this, that your strength to stand and overcome must not be expected from graces received in the past -- but from the fresh and renewed influences of heaven. You must lean more upon Christ than your duties; you must lean more upon Christ than upon your spiritual tastes and discoveries: you must lean more upon Christ than upon your graces, or else Satan will lead you into captivity," (Kindle location 3464-3488).
"Watch and pray, that ye enter not into temptation: the spirit indeed is willing, but the flesh is weak," (Matt. 26:41).