The author talks about ki or ch'i, the "latent power" within man that is practiced in many martial arts. While ki is an ancient belief, it is based in fact. Many non martial art sports trainers and sports practitioners talk about being in the “in the zone.” A state where reality seems to slow so that the person may react quicker and more precisely, where adrenaline flows freely and pain is ignored, which gives the person seemingly super human abilities. This effect is a scientifically proven process that occurs in the body during periods of extreme stress and it may be trained to occur on demand, such as is done in the martial arts. It is not some mystical latent power.
Since the feats performed while in “the zone” or using ki have been scientifically documented, it is difficult for the author to disprove them, so he comes up with a unique explanation for their existence. He says the powers come from, and are controlled by, an alien force within the body. The author states that even Jesus had to have "the power of the Lord" present within Him for Him to heal others. The author says ki cannot be from God because His power cannot be used in this manner, and, since the author has concluded that man does not have the ability to this on his own, there can only be one other source—Satan. Therefore, according to the author, anyone who uses ki is actually possessed by Satan or his demons. The author says that Satan also deludes these people into thinking that they have accomplished these feats through their own training and abilities, which means they do not realize they are possessed. However, the author in his infinite wisdom and belief in God is able to recognize the demonic possession, and, of course, he also has the solution—the martial artist must believe in the author’s form of religion, stop training in the martial arts, and reject the demons.
The author states that martial arts are generally divided into two categories: "hard, or external" and "soft, or internal." This is true, however, the author then states that the hard arts involve less occultism than do the soft arts since they emphasis physical training more than do the soft arts, which rely on the cultivation of so called "energy fields." Therefore, the author thinks the hard arts are less into occultism, but since they do teach such things as deep breathing, meditation, and use of the kiai, he says they too will corrupt their practitioners at some point. So, there is good news and bad news for new Taekwondo students, you are probably free of demons, at least for now, but after a few years of training, you may be harboring a demon or two.