Well, I read one website that was in favor of being slain in the Spirit and they appeared at first glance to make a good argument, but after reading this portion of the article below by Professor Johan Malan from South Africa, I believe they are wrong.
"During falling in the Spirit in meetings people always fall backward to have a positive experience with the Holy Spirit. The Bible, however, mentions four instances where people fell down backward as examples of God’s judgment and rejection because of their infidelity and sin:
1. “Dan shall be a serpent by the way, a viper by the path, that bites the horse’s heels so that its rider shall fall backward” (Genesis 49:17).
2. “Then it happened... that Eli fell off the seat backward by the side of the gate; and his neck was broken and he died” (1 Samuel 4:18).
3. “But the word of the Lord was to them, precept upon precept, precept upon precept, line upon line, line upon line, here a little, there a little, that they might go and fall backward, and be broken and snared and caught” (Isaiah 28:13).
4. “Then – when He said to them, I am He – they drew back and fell to the ground” (John 18:6).
John 18:6 is commonly used by supporters of falling in the Spirit. However, the following needs to be said about this practice from a biblical point of view:
Firstly, the people who allegedly fell in the Spirit in John 18:6 were the enemies of Christ, including Judas Iscariot.
Secondly, the falling backward was not a condition of unconsciousness or fainting. It was rather a reaction of shock by lost people after meeting the Lord. John 18:6 can, therefore, not be used as justification for the present practice of falling in the Spirit, because it clearly suggests that those who fell down were lost sinners.
Thirdly, in the Bible people fell forward on their knees or face. Every time when that happened (about 30 times) the results were good and profitable.
The following Scriptures are used in defense of falling in the Spirit: Genesis 17:3; Numbers 16:4; Numbers 24:4; Leviticus 9:24; Joshua 5:14; Judges 13:20; 1 Kings 18:39; 1 Chronicles 21:16; Ezekiel 1:28; Ezekiel 2:1-2; Ezekiel 3:23; Ezekiel 43:4; Ezekiel 44:4; Daniel 8:17; Daniel 10:9; Matthew 2:11; Matthew 17:6; Matthew 28:1-4; Mark 5:33; Luke 5:8; Luke 8:47; Luke 17:16; Acts of the Apostles 9:4 or Acts of the Apostles 26:14; Acts of the Apostles 16:29; 1 Corinthians 14:25; 2 Corinthians 12:2-4; Revelation 1:17; Revelation 4:10; Revelation 5:8; Revelation 19:4.
Although supporters of falling in the Spirit use these scriptures to justify their practice, the contrary is true. These verses explicitly refer to a falling forward on the knees or face. That was mostly a conscious act: “Then Abram fell on his face, and God talked with him” (Genesis 17:3).
It was also a traditional way of greeting and a form of showing respect when people bowed down before their king, or slaves subjected themselves to their lords. It was also a sign of humbling and showing respect and fear to a holy God – cf. Peter who fell down at the knees of Jesus (Luke 5:8), Paul’s conversion in Acts of the Apostles 9:4, and John humbling himself on Patmos when he fell down at the feet of Jesus (Revelation 1:17).
In ancient times it was the most natural thing to fall on your knees or face to take on a position of prayer or honoring someone. It was in no way associated with fainting or incoherent talk. In Matthew 2:11, the wise men “fell down and worshipped [the Child]”. 1 Corinthians 14:25 refers to a member of a congregation, “falling down on his face, he will worship God and report that God is truly among [us].”
The reason for the falling down was not, as some people say, that the person was stricken down by the Spirit of God. The Bible never says that the Holy Spirit struck people down. They fell because of one the following human reactions:
Fear (Numbers 16:4; Joshua 5:14; Judges 13:20; Daniel 8:17; Daniel 10:9; Matthew 17:6; Matthew 28:1-4; Luke 8:47; Acts of the Apostles 9:4).
Joy and thanksgiving for blessings (Leviticus 9:24; Matthew 2:11; Mark 5:33; Luke 17:16).
Honor, humbling and worship in the presence of God (1 Kings 18:39; 1 Chronicles 21:16; Ezekiel 1:28; Ezekiel 2:1-2; Ezekiel 3:23; Ezekiel 43:4; Ezekiel 44:4; Luke 5:8; 1 Corinthians 14:25; Revelation 1:17; Revelation 4:10, Revelation 5:8; Revelation 19:4).
The Spirit of God rather set people on their feet than striking them down. When people have fallen down because of one of the reactions mentioned above, it is often said that the Spirit of God raises them to stand upright. Ezekiel says, “...the glory of the Lord stood there... and I fell on my face. Then the Spirit entered me and set me on my feet” (Ezekiel 3:23-24).
Even the falling forward gets little Scriptural support or encouragement because God, Jesus or an angel often tells people to stand up (Ezekiel 2:1-2; Ezekiel 43:3; Daniel 8:17-18; Daniel 10:9-10; Matthew 17:6-7). In Matthew 17:7 Jesus said to His disciples who fell on their faces because of fear: “Arise, and do not be afraid.” The Holy Spirit is rather associated with the act of rising than with falling.
There is indeed a spirit that makes people fall down, but that is not the Spirit of God – that is an evil spirit. There are various examples of this in the Bible. Mark says, “For [Jesus] healed many, so that as many as had afflictions pressed about Him to touch Him. And the unclean spirits, whenever they saw Him, fell down before Him and cried...” (Mark 3:10-11). In another case a boy with a mute spirit was brought to Jesus, “and wherever [the spirit] seizes him, he throws him down... Then they brought him to [Jesus]. And when he saw Him, immediately the spirit convulsed him, and he fell on the ground and he wallowed” (Mark 9:18-20). After Jesus rebuked the spirit and commanded him to leave He assisted the boy to get up: “Jesus took him by the hand and lifted him up, and he arose” (Mark 9:27). A case has also been recorded in Capernaum where Jesus delivered a man who was possessed by an unclean spirit: “Jesus rebuked him, saying, Be quiet and come out of him! And when the demon had thrown him in their midst, it came out of him and did not hurt him” (Luke 4:35).
The supporters of falling in the Spirit also have a big problem to prove from the Bible that this experience may be linked to a baptizing (or anointing) with the Holy Spirit. Except for cases where people had problems with demons and fell down during the process of deliverance, there is no relationship in the Bible between healing or anointing with the Spirit and falling in the Spirit. The supporters of this strange experience have a double problem: firstly, to find a similar phenomenon in the Bible, and secondly, to connect this experience to baptizing with the Holy Spirit.
Easy salvation
The normal way in which God deals with sinners – i.e. through repentance and faith in the Lord Jesus – is brushed aside and substituted by a strange experience such as falling in the Spirit. In this way, biblical truths are ignored or wrongly applied. In this way salvation is made easier and cheaper, i.e. without repentance and counting the cost by those involved.
Falling in the Spirit is used as a crush-pen for salvation through which people are forced or manipulated; consequently, they are not confronted with a choice whether they wish to repent or not. The experience of falling in the Spirit replaces a conscious decision that sinners must make when they are convicted of their sins. Suddenly, they find themselves in a mystical trance. After recovering their consciousness, they regard themselves as believers who were changed by the power of God.
Because of this way of dealing with lost people, preaching the gospel of salvation has virtually become redundant – unbelievers only need to fall in the Spirit. But the problem is that such people’s lives are not built upon the foundation of Christ but upon a mystical experience. In this way, the biblical message of repentance is bypassed. That is one of the reasons why preaching on sin has become such a rare feature of modern evangelization.
It obviously does not trouble the leaders of this movement that the basis of salvation through falling in the Spirit is unbiblical. Coppin says, “Even if there were no biblical basis for the phenomenon, it might be contended that since many are strengthened through the experience, it is worth entertaining.” The general approach is: “Be open to new ways in which God by His Spirit may be speaking to the Church.”
The distorted view that unsaved people, who are still in bondage of sin, may have certain experiences with the Holy Spirit is completely foreign to Scripture. The biblical way of salvation is that the Holy Spirit first convicts people of their sins. Only after they have confessed and forsaken their sins and put their trust in the Lord Jesus to save their souls by virtue of His work of atonement on the cross, are they regenerated by the Holy Spirit who will then establish His presence in these persons’ hearts. After the experience of being born again they must continuously be filled with the Spirit.
It also does not make any sense that people can have many experiences of falling in the Spirit. Some people refer to the new experiences as a recharge. It is obvious that a deeply-rooted discontentment and opportunism lies at the basis of falling in the Spirit. Sinners are looking for an easy and physically tangible way to become Christians without really changing their lifestyles. Many Christians are not content with the normal views about spiritual growth and are looking for extraordinary experiences in their spiritual lives. They want to be baptized in the Spirit in one dramatic moment and also obtain special gifts to enhance their boring lives. This approach opens the way to various forms of deception.
In this way, the door is opened to the sensual and the spectacular, thereby enthroning the flesh. A humanistic self-image is stimulated which may have an outward appearance of the person being Christian, but in reality he/she has no inclination towards true spirituality. The new gifts and strange manifestations are used to glorify the self, and are practiced for entertainment rather than the promotion and extension of God’s kingdom on earth.
The Holy Spirit warned us that in the last days the devil will succeed in even seducing believers to accept wrong doctrines which are propagated by deceiving spirits: “Now the Spirit expressly says that in the latter times some will depart from the faith, giving heed to deceiving spirits and doctrines of demons” (1 Timothy 4:1). John says, “Beloved, do not believe every spirit, but test the spirits, whether they are of God; because many false prophets have gone out into the world” (1 John 4:1)."