"Slain in the spirit" is not of the Lord. They are drinking from a different fountain.
Proverbs 25:26 A righteous man falling down before the wicked is as a troubled fountain, and a corrupt spring. 27 It is not good to eat much honey: so for men to search their own glory is not glory. 28 He that hath no rule over his own spirit is like a city that is broken down, and without walls.
Believers that "fall" for it are actually falling away from the faith when they do, because they are testifying to the spirit showing up when they fall thus assuming that was the Holy Spirit when it was not, because the Holy Spirit was already in them and so that was not the Holy Spirit making them fall, especially when God is not the author of confusion.
1 Corinthians 14:32 And the spirits of the prophets are subject to the prophets. 33 For God is not the author of confusion, but of peace, as in all churches of the saints.
Since one of the fruits of the Spirit is temperance which is "self-control", how then can that manifestation be of Him when believers lose control and fall against their will; and it isn't to bow to God in acknowledging His Presence either when they are "out of it".
Paul testified that there is only one drink of the One Spirit that all believcers share like testimony in.
1 Corinthians 12:13 For by one Spirit are we all baptized into one body, whether we be Jews or Gentiles, whether we be bond or free; and have been all made to drink into one Spirit.
So when someone preaches another spirit to receive or another drink... that is not of Him.
2 Corinthians 11:1Would to God ye could bear with me a little in my folly: and indeed bear with me. 2 For I am jealous over you with godly jealousy: for I have espoused you to one husband, that I may present you as a chaste virgin to Christ. 3 But I fear, lest by any means, as the serpent beguiled Eve through his subtilty, so your minds should be corrupted from the simplicity that is in Christ. 4 For if he that cometh preacheth another Jesus, whom we have not preached, or if ye receive another spirit, which ye have not received, or another gospel, which ye have not accepted, ye might well bear with him.
2 Corinthians 13: Examine yourselves, whether ye be in the faith; prove your own selves. Know ye not your own selves, how that Jesus Christ is in you, except ye be reprobates?
This is the prophetic hypocrisey talked about where believers will acknowledge that He is in us, but they still seek to receive Him again, opening themselves up to other spirits & following after the doctrines of devils in being an adulterous generation seeking after a sign.
1 Timothy 4:1Now the Spirit speaketh expressly, that in the latter times some shall depart from the faith, giving heed to seducing spirits, and doctrines of devils; 2 Speaking lies in hypocrisy; having their conscience seared with a hot iron;
Matthew 12:39But he answered and said unto them, An evil and adulterous generation seeketh after a sign; and there shall no sign be given to it, but the sign of the prophet Jonas:
This was the falling away from the faith that Paul warned believers about as that iniquity was already at work in his day.
2 Thessalonians 2:7 For the mystery of iniquity doth already work: only he who now letteth will let, until he be taken out of the way.....9 Even him, whose coming is after the working of Satan with all power and signs and lying wonders, 10 And with all deceivableness of unrighteousness in them that perish; because they received not the love of the truth, that they might be saved. 11 And for this cause God shall send them strong delusion, that they should believe a lie: 12 That they all might be damned who believed not the truth, but had pleasure in unrighteousness.
Those that believe the lie that they can receive the Holy Spirit "again", God will permit the strong delusion to occur, as the Holy Spirit, still being in them, BUT He will not restrain seducing spirits from coming in when believers are seeking after them for a sign.
Paul reminded believers in the face of this apostasy when they had actually received the sancitification of the Spirit & the belief of the truth and that was by the hearing of the gospel.
2 Thessalonians 2:13 But we are bound to give thanks alway to God for you, brethren beloved of the Lord, because God hath from the beginning chosen you to salvation through sanctification of the Spirit and belief of the truth: 14 Whereunto he called you by our gospel, to the obtaining of the glory of our Lord Jesus Christ. 15 Therefore, brethren, stand fast, and hold the traditions which ye have been taught, whether by word, or our epistle.
Those that have fallen away are not to be treated as the enemy, but to be admonished as a brother by withdrawing from their company so that they may be ashamed as Paul explains further into the next chapter in addressing this apostasy where disorder is manifested.
2 Thessalonians 3:1Finally, brethren, pray for us, that the word of the Lord may have free course, and be glorified, even as it is with you: 2 And that we may be delivered from unreasonable and wicked men: for all men have not faith. 3 But the Lord is faithful, who shall stablish you, and keep you from evil. 4 And we have confidence in the Lord touching you, that ye both do and will do the things which we command you. 5 And the Lord direct your hearts into the love of God, and into the patient waiting for Christ. 6 Now we command you, brethren, in the name of our Lord Jesus Christ, that ye withdraw yourselves from every brother that walketh disorderly, and not after the tradition which he received of us. 7 For yourselves know how ye ought to follow us: for we behaved not ourselves disorderly among you;.....14 And if any man obey not our word by this epistle, note that man, and have no company with him, that he may be ashamed. 15 Yet count him not as an enemy, but admonish him as a brother.
It is hoped that those that have fallen away, God may be peradventuring to recover them from this snare of the devil by returning to their first love, shun vain & profane babblings, and seek their edification from the written word in the KJV and pray normally so that they may know what they had prayed for to give the Father genuine thanks in Jesus's anme for answered prayers. And may they lean on Jesus Christ to certainly chase no more after the "Holy Spirit" to be received after a sign as people in the world do when receiving other spirits.
John 14:16 And I will pray the Father, and he shall give you another Comforter, that he may abide with you for ever; 17 Even the Spirit of truth; whom the world cannot receive, because it seeth him not, neither knoweth him: but ye know him; for he dwelleth with you, and shall be in you.
Hebrews 11:1Now faith is the substance of things hoped for, the evidence of things not seen. 2 For by it the elders obtained a good report.....
Galatians 3:14 That the blessing of Abraham might come on the Gentiles through Jesus Christ; that we might receive the promise of the Spirit through faith.....26 For ye are all the children of God by faith in Christ Jesus.
The real indwelling Holy Spirit & scripture keeps pointing saved believers to keep their eyes on the Son of God, the Bridegroom, in living that reconciled relationship with God thru Jesus Christ as the Son is the only way we can have that fellowship with God the Father as it should be, since the abiding bride of Christ is to be relating to God thru the Bridegroom for He shall be coming soon.
1 Corinthians 1: 9 God is faithful, by whom ye were called unto the fellowship of his Son Jesus Christ our Lord. 10 Now I beseech you, brethren, by the name of our Lord Jesus Christ, that ye all speak the same thing, and that there be no divisions among you; but that ye be perfectly joined together in the same mind and in the same judgment.