The Old Testament law commanded the Israelites, “Ye shall not make any cuttings in your flesh for the dead, nor print any marks upon you: I am the Lord.” (Leviticus 19:28) Christians are not under the Old Testament law. (Romans 10:4; Ephesians 2:15) While we are not under this law, because God commanded this to the Israelites, we should pause and think. The New Testament does not say anything specifically about tattoos and body piercing.
The Bible is not a book of minute laws, it is a book of general principles. This is good because if it were a book of minute laws it would take a train with several cars to carry them. It is also good because you may find a loophole in a law, but you can not in a principle. For example: The Bible does not say, “thou shalt not watch X rated movies.” The Bible does say that a man is not to look upon a woman for the purpose of lusting after her. (Matthew 5:28)
An important scriptural principle about how we treat our bodies is recorded in I Corinthians, “What? know ye not that your body is the temple of the Holy Ghost which is in you, which ye have of God, and ye are not your own? For ye are bought with a price: therefore glorify God in your body, and in your spirit, which are God’s.” (I Cor. 6:19-20)
Each Christian should personally seek God’s permission before doing anything to his body that might be offensive to other Christians or God.