Years ago, someone told me about Jesse Penn-Lewis and War on the Saints. If I had to pick a book that has taught more about true warfare for the christian, it would be this one. Below is an excerpt from the book.

“Knowledge and all discernment; so that ye may prove the things that
differ, that ye may be sincere and void of offence. . . .” Phil. 1: 9,10, m.

True. Counterfeit.
1. The Baptism, or Fullness of the Spirit: An influx of the Spirit of God into the human spirit, which liberates the spirit from the soul (Heb. 4: 12), so as to become a pliable organ or channel for the outflow of the Spirit through the believer, manifested in witness to Christ and in aggressive prayer service against the powers of darkness.It is a true baptizing into the Body of Christ, and oneness with all the members of the Body. Its special mark and result is known in power to witness for Christ, and in conviction of sin in others, and their turning to God.

The highest manifestation of the Fullness of the Spirit is co-existent with the use of the faculties and self-control.

There is but one reception of the Holy Spirit: with many succeeding experiences, developments, or new crises, resultant on fresh acts of faith, or apprehension of truth; various believers having varied degrees of the same Infilling of the Spirit, according to individual conditions. The enduement of power for service is often a definite experience in many lives. Pages 50, 291, 297.

1. Counterfeit workings of evil spirits may accompany a true reception of the Fullness of the Holy Spirit, if the believer “lets go” his mind into “blankness,” and yields his body up passively to supernatural power. As a “blank mind” and “passive body” is contrary to the condition for use required by the Holy Spirit, and is the primary condition necessary for evil spirits to work, the anomaly is found in the Holy Spirit responding to the law of faith, and filling the man’s spirit, at the same time that evil supernatural powers respond to the law of passivity fulfilled in mind and body. They then can produce in the senses manifestations, which seem to be the outcome of the Holy Spirit’s entry to the spirit.The results of the counterfeit manifestations are varied, and wide in their ramifications, according to individual conditions. The abstract result is great “manifestations” with little real fruit; “possession” by evil spirits of the mind and body in varied degrees; a spirit of division from others, instead of unity, etc., etc. Pages 54, 97, 106, 107, 108.
2. The Presence of God: Known in and by the human spirit, through the Holy Spirit. When He fills the atmosphere of a room the spirit of the man is conscious of it, not his senses. The faculties of those present are alert and clear, and they retain freedom of action. The spirit is made tender (Psa. 34: 18), and the will pliable to the will of God. All the actions of a person moved by the true and pure Presence of God are in accord with the highest ideal of harmony and grace. Pages 104, 107. 2. The counterfeit of the Presence of God is mainly felt upon the body, and by the physical senses, in conscious “fire,” “thrills,” etc. The counterfeit of the “Presence” in the atmosphere is felt by the senses of the body, as “breath,” “wind,” etc., whilst the mind is passive or inactive. The person affected by this counterfeit “presence” will be moved almost automatically to actions he would not perform of his own will, and with all his faculties in operation. He may not even remember what he has done when under the “power” of this “presence,” just as a sleep-walker knows nothing of his actions when in that state. The inaction of the mind can often be seen by the vacant look in the eyes. Pages 109, 112, 124, 128, 130.
3. God in and with man in the spirit: John 14: 23. The Father in heaven is realized to be a real Father (Gal. 4: 6), the Son a real Saviour, the Holy Spirit a real Person; manifested as One in the spirit of the believer, by the Holy Spirit: with resulting effects as in Rom. 8: 9-11. Pages 103, 130. 3. Evil spirit’s counterfeit, as the occasion serves them, each Person of the Trinity, and can thus obtain access, and become in and with a man in manifestations given to the senses, in which the real spirit-sense may have no part. Pages 52, 103, 104, 105, 108.
4. Christ manifested in the believer by His Spirit, so that He is known as a Living Person on the Throne in heaven, and the believer joined in spirit to Him there, with the result that Christ’s life and nature is imparted to him, forming and building up in him a “new creation,” (Gal. 1: 16; 4: 19. Col. 1: 27), the believer growing up into Him in all things.note 1 Pages 103, 107, 126, 127, 289. 4. Christ apparently manifested inwardly as a “Person,” to whom the soul prays, or with whom he holds communion, yet there is no real evidence of the expression of the Divine nature, or true growth of the Christ life, with a deepening fellowship with the Christ in heaven. On the contrary the Christ in heaven seems far away. The counterfeit centres and ends in an “experience” which keeps the person introverted or self-centred (spiritually). Page 107. Cf. pp. 289, 290, 291.
5. Consciousness of God: Felt in the spirit, and not by the physical senses. Pages 107, 108. 5. “Consciousness” of “God” in bodily sensations, which feed the “flesh” and overpower the true spirit-sense. Pages 106, 130.
6. The Holiness of God: when realized by the believer produces worship and godly awe, with a hatred of sin. On the ground of the Blood of Calvary God draws near to men, seeking their love, but His presence does not terrorize. Page 289. 6. Evil spirits counterfeit this by giving a terror of God, which drives men away from Him, or forces them into actions of slavish fear, apart from the use of the mind, and volition, in glad voluntary obedience to Him. Page 143.
7. Surrender to God: Of spirit, soul and body, is a simple yielding or committal to Him of the whole man, to do His will and be at His service. God asks the full co-operationnote 2 of the man in the intelligent use of all his faculties. Rom. 6: 13. Page 70. 7. Passive yielding of spirit, soul and body to supernatural power, to be moved automatically, in passive, blind obedience, apart from the use of volition or mind. Evil spirits desire “control” of a man, and his passive submission to them. Pages 68, 69.
8. Fellowship with the sufferings of Christ: The result of faithful witness for Him, and in such “suffering,” the joy of the Spirit breaks forth in spirit. (Acts 5: 41). The fruit of true conformity to Christ’s death in the “fellowship of His sufferings” is seen in life to others, and growth in tenderness of spirit, and Christ-likeness in character. 2 Cor. 4: 10-12. Page 89. 8. “Suffering” caused by evil spirits is characterized by a fiendish acuteness, and is fruitless in result–the victim being hardened instead of mellowed by it. The demons can cause anguished suffering in spirit, soul or body. “Possession” manifested in abnormal suffering, may be the fruit of (unconscious) acceptance of sufferings caused by evil spirits, often under the name of the “will of God.” Pages 88, 89, 90.
9. Trusting God: A true faith given of God in the spirit, having its origin in Him, without effort reckoning upon Him to fulfil His written Word. Co-existent with the full use of every faculty in intelligent action. “Faith” is a fruit of the Spirit and cannot be forced. Gal. 5: 22. 2 Cor. 4: 13. Page 275. 9. “Trusting evil spirits” comes about through trusting blindly some supernatural words, or revelations, supposed to come from God, which produces a forced “faith,” or faith beyond the believer’s true measure, the result being actions which lead into paths of trial never planned by God. Pages 129, 135, 274, 275.
10. Reliance upon God: An attitude of the will, of trust and dependence upon God, taking Him at His word, and depending upon His character of faithfulness. Page 127. 10. Reliance upon evil spirits means a passive leaning upon supernatural help and experience, which draws the person away from faith in God Himself, and from active co-action with Him. Page 143.
11. Communion with God: Fellowship in the Spirit with Christ in the glory as one spirit with Him. The consciousness of this is in the spirit (John 4: 24) only, and not in “feelings” in the senses. See for conditions of true communion with God, 1 John 1: 5-7. Page 291. 11. “Communion” with evil spirits may take place by retiring within to enjoy sense communion, in “exquisite feelings” which absorbs and renders the soul incapable of the duties of life. The “flesh” is fed by this spurious spiritual “communion” as really as in grosser ways. Pages 124, 125, 155.
12. Waiting on God: The spirit in restful co-operation with the Holy spirit, waiting God’s time to act, and a waiting for Him to fulfil His promises. The true waiting upon God can be co-existent with the keenest activity of mind and service. Page 62-63. 12. A “waiting for the Spirit to come,” in hours of prayer, which brings those who “wait” into passivity, which at last reaches a point of “séance” conditions, followed by an influx of lying spirits in manifestations. Pages 62, 63.
13. Praying to God: Having access to the Holiest of all, on the ground of the Blood (Heb. 10: 19). Penetrating in spirit through the lower heavens to the Throne of Grace. Heb 4: 14-16. True “prayer” is not directed toward God as within the believer, but to a Father in heaven, in the Name of the Son, by the Holy Spirit. Page 126. 13. Praying to evil spirits comes about by praying to “God” in the atmosphere, or within, or possibly to “pictures” of God in the mind; instead of approaching the Throne of Grace according to Heb. 10: 19. Pages 95, 130
14. Asking God: An act of the will in simple faith, making a transaction with God in heaven, on the ground of His written Word. “Answers to prayer” from God are usually so unsensational and so unobtrusive that the petitioner often does not recognize the answer. Cf. pages 249, 276, 279. 14. “Asking” evil spirits, by speaking to some supernatural presence in, or around the person. The “answers” are generally “dramatic,” sensational, calculated to over-awe the person, and make him feel he is a wonderful recipient of favour from on high. By this means the demons gain control over him. Pages 118, 119, 142.
15. God speaking: Through His Word, by His Spirit, in the spirit and conscience of the man, illuminating the mind to understand the will of the Lord. Page 136. 15. Evil spirits speaking, wither puffing up, accusing, condemning or confusing the person, so that the is bewildered or distracted and cannot exercise his reason or judgment. The “speaking” of accusing spirits resembles the “thinking,” or speaking to oneself, when the words are not uttered audibly. Pages 170, 171. Also “Listening” on pages 119, 125, 136, 142, 143.