Have you had your devotions in the Old Testament book of Leviticus lately? If you hang in there long enough you will discover in 19:28 that tattoos are forbidden. But are they today? This is a subset of a question pertaining to a believer’s relationship to the Law of the Old Testament.
Here is very helpful article that explores the ins and outs: UNDER THE NEEDLE: AN ETHICAL EVALUATION OF TATTOOS AND BODY PIERCINGS by Lorne Zelyck