Is the prohibition taking the tattoos valid in the New Covenant? I believe that it is valid and give you these verses.
2 Pe 1:
1 ¶ Simon Peter, a servant and legate of Jesus the Messiah,—to those who have obtained equally precious faith with us, through the righteousness of our lord and Redeemer, Jesus the Messiah;—
2 may grace and peace abound to you through the recognition of our lord Jesus the Messiah,
3 as the giver to us of all things that be of the power of god, unto life and the fear of god, through the recognition of him who hath called us unto his own glory and moral excellence:
4 wherein he hath given you very great and precious promises; that by them ye might become partakers of the nature of god, while ye flee from the corruptions of the lusts that are in the world.
The New Testament shows us that how we must serve and believe in God. God has given to us the Holy Spirit as the power and aid that we can understand what the Bible teaches.
If we could believe in God by taking the tattoo, in which is Bible verses or reads the Lord Jesus and so on, so this kind of command should be in the Bible. Tattooing was very common in the world where apostles lived. If the will of God would have been to make "Biblical" tattoos, so God would have said that you must make those kinds of tattoos. However, in the New Testament is not a command to make tattoos. For this reason, I don't believe that it is the will of God to take the tattoos.
The Bible teaches us that serving of God is not the outward issue, but inward. Believer testimony and faith must be the inward issue by the Holy Spirit accordance with the word of God. God said by the prophet Jeremiah that in the New Covenant, God puts His law to inwards parts and writes His law to the hearts of His people. Biblical faith must be written to inner man to his heart and not outwardly to his skin.
Ro 10:10 For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation.
The Bible doesn't teach serving God by the tattoos, so tattooing is against the will of God.
The whole article is here:
http://koti.phnet.fi/petripaavola/Bibleandtattoos.html