Leviticus 19: 28 is the only Scripture that directly refers to tattoos: “And cuttings for a dead person shall ye not make in your flesh, nor put any tattoo writing upon you”. However, this translation is not certain. Normally you would get help as to the meaning of a word by understanding how it is used elsewhere in the Bible, but the Hebrew word behind tattoo writing occurs nowhere else in Scripture. This should make us very cautious as to what we make of the verse. The context of “cuttings for a dead person” could well suggest that a specific association with religious purposes is in view (see 1 Kings 18: 28; Jer. 41: 5).
It also needs to be borne in mind that as Christians we are not given a list of prohibitions (which even the unspiritual and unbelieving can adhere to). The Christian way is “walk in [the] Spirit, and ye shall no way fulfil flesh’s lust” (Gal. 5: 16). We are not in a legal system, but arrive in our own souls that some things are to be avoided. How then is this brought about? Because “the unction which ye have received from him abides in you” (1 John 2: 27) and the believer’s senses are progressively exercised to distinguish between good and evil (see Heb. 5: 14). Using OT commandments to enforce NT living is really the Galatian error. We “serve in newness of spirit, and not in oldness of letter” (Rom. 7: 6). Of course it is true that some of the matters brought up in the OT are re–stated in the NT, but tattoos are not one of them. To argue against them on the basis of Lev. 19: 28 is thus a weak and simplistic argument—indeed, to be consistent, it also ought to be reasoned that Christians should not shape their beards (see v27)!
I would be inclined to leave Lev. 19: 28 aside as a reference of interest on the subject of tattoos, but one that is hardly definitive on the subject. We are on far safer ground arguing from 1 Cor. 6: 20: “ye have been bought with a price: glorify now then God in your body”. Most modern–day tattoos seem to be designed either to minister to the flesh, or are verging on the unpleasant or evil. That makes it very simple for the believer—most tattoos do not glorify God, and nor (significantly) do those who make a trade of applying them. The argument that Bible texts could be used is a poor one since there is no foundation for this in Scripture. Our most powerful act of evangelism is when we are living epistles of Christ, and men read our lives (see 2 Cor. 3: 2, 3). One more comment: I need hardly say that there is also a world of difference between what a convert has done in a past life, and a professing Christian seeking a tattoo after conversion.