I have studied and read some of the ancient rites that other nations practiced in regards to tattoos and cutting themselves. For a follower of Jesus, how would Leviticus 19:28 relate for today?
The common interpretation of Leviticus 19:28 is that it prohibits what we would call tattoos for those under the Covenant of Moses. I am not an expert on the Hebrew which is translated as “tattoo marks” in the NIV, but let us assume that is the meaning.
OK, then what is the application to Christians who are not under the Law of Moses? The simple answer is that there is no application. We are not required to observe the Sabbath, to go to a priest if we have skin diseases, to refrain from pork, to make grain offerings or any of dozens of other requirements found in the Law of Moses. For someone like me (and probably for you as well) who finds tattoos to be silly and just plain a really bad idea, it is tempting to use Leviticus 19:29 to “prove” that tatoos are sinful, but I do not think we can do this with the passage unless we want to carry the entire Mosaic Law into Christianity, which none of us want to do (Colossians 2:13-19 and the entire book of Galatians).
So… my answer is that is no application to Christians today, unless an individual Christian chooses to use the passage as a personal reason to personally choose not to have tattoos and give advice (but not authoritative command) to our friends. Feel free to give this advice. I do. But do not fall into the trap which Paul very strongly condemns in Galatians.