The concept of yin and yang originates in ancient Chinese philosophy and has been identified with the philosophical religions of Confucianism, Buddhism and Taoism. The yin and yang philosophy states that two primal opposing but complementary forces are found in all things in the universe.
Yin, the darker element, is described as being passive, dark, feminine, downward-seeking and corresponds to the night. Yang, the brighter element, is described as being active, light, masculine, upward-seeking and corresponds to the day. Yin is often symbolized by water, while yang is symbolized by fire. The belief that the opposites of yin and yang create balance in life has come to mean “peace” in pop culture.
The main thing to understand about most Asian philosophies and religions is that they are essentially nontheistic, which means that God is not a part of those philosophies of life. This is not to say there is no belief in the spirit world, but that they do not include any focus on God.
Because many Asian philosophies are essentially “godless,” their views on life are drastically different than those presented in the Bible which places God as the center of all things. For example, good and evil are recognized in yin and yang, but one is not more powerful than the other. It is believed that good creates evil and evil creates good, therefore one should not attempt to rid the world of evil or create a society of all good. However, if we look at the Word of God, 1 John 1:5 tells us “God is light, and in him is no darkness at all.” Regarding Satan, John 8:44 says there is no truth in him.
The question of whether or not a Christian should wear jewelry and clothing with the yin yang (also called tai chi) basically comes down to the question of, “Why would a Christian want to promote a godless philosophy of life?” As Christians, our goal should be to lead people to God and to focus on the true peace that can only come from a relationship with Jesus Christ instead of the philosophies of men.
Questions also arise as to whether or not the yin yang/tai chi is “satanic” or an element of witchcraft. In many common markets today, the image itself no more promotes Satan than it does God. But evil always exists where God is pushed away, and those who really study and live by Asian philosophies will usually pull further away from God rather than closer to Him. So while the symbol is not essentially “satanic,” it is definitely not godly and therefore not profitable for the Christian.