So i would like to state something. If you are a Christian, it is not sinful. I have longish hair. I am a Christian. The books of the law in the Old Testament stated quite clearly, that long hair and tattoos were prohibited to the Jews. However, the Old Testament were books for the Jews to follow and understand. With the death and resurrection of Christ, the Old Testament became null and void to the new race of believers, Christians. The Old testament is strictly followed by the Jews, whereas the New Testament is for the Christians to follow. The New Testament has never mentioned the laws of the Old Testament with the exception of a select few, among which hair and tattoos are not a part of. Therefore, to a modern believer, Christians are not being sinful by having long hair, or tattoos unless the tattoos are blasphemous to God. With the popularity aspect of things, as long as the popularity does not extend to dishonoring God, then you will be fine. Therefore, under most circumstance, you are correct, although Wraya has accurate points, but mainly if you are a Jew, or dishonoring God with your tattoos, and what you do to be popular. However, you are mainly correct.