I didn't say that, please don't misquote me. What i meant was, if you go to church BEFORE you have tattoos, then you should not have them, because the Bible tells us that the body is a Temple Of God, and we should respect it, so we shouldn't mutilate it. As is the same with smoking, piercings, etc. This is directly disobeying God's commandments to us, it is akin to breaking the law on a much larger scale, from a Christian POV. That is my take. For example, you wouldn't trash your precious five-figure guitar just to try out, or cause your friends are trashing theirs.
If one has tattoos and after that he goes to church, there is no hard and fast rule that says he cannot be allowed in, or that we should be judgmental and condemn him. Quite the opposite, actually. We should love others as ourselves.
I am not here to preach, i am here to express my views from a Christian's point on why one should not have tattoos or do other things that is detrimental to both our body and relationship with God. I don't know about other religions, but in Christianity, we are taught we should not mutilate our bodies, be it through piercings, tattoos etc.