I've just ordered this and its sequel, for next week, I as a Christian myself do not believe Martial Arts are 'The Spawn of Satan'. It is the individual fighters who use it to commit murder are the Evil ones.
MA teaches humility etc, we have Kokoro (Attitude), this is a concept that crosses through many martial arts, but has no single discrete meaning. In context, it means something like "heart," "character," or "attitude." Character is a central concept in karate, and in keeping with the dō nature of modern karate, there is a great emphasis on improving oneself. It is often said that the art of karate is for self-defense; not injuring one's opponent is the highest expression of the art. Some popularly repeated quotes implicating this concept include:
"The ultimate aim of Karate lies not in victory or defeat, but in the perfection of the character of its participants." - Gichin Funakoshi
"The Way is not meant as a way of fighting. It is a path on which you travel to find your own inner peace and harmony. It is yours to seek and find." - Hironori Ohtsuka
Respect is another very important part of karate; it is about cleansing oneself and strengthening character. The spirit of "osu" is to push onself to the limit of one's ability, to persevere under pressure, to endure. This is why it is said that "Karate always begins and ends with rei."
This is "Christian" not "Satanic"