Here is the questions I originally received that motivated me writing about tattoos:
“Doesn’t Leviticus tell us not to have tattoos and doesn’t 1 Corinthians say that our bodies are temples?”
Here was my response:
1 Cor 6:19 that says that “your body is the temple of the Holy Spirit who is in you,” but this passage is clearly referencing sexual immorality, not tattoos, caffeine, or smoking, etc. and saying not to join the temple to a “harlot”. 
Our bodies are the temple of the Holy Spirit, but I don’t think you can make the argument that anything that is bad for the body is therefore morally bad automatically, then; unless you also make an appeal against virtually everything unhealthy!  I also don’t think it is a good idea to connect these passages to the Old Testament commands.
Now, it is important that our bodies are the temple of the Holy Spirit.  It means our bodies are important – not just waste material, or meaningless shells like Yoda says, but the temple of God’s Spirit!  This passage also can be a passage that will convict us to take care of what we do with our bodies.  We cannot make use of this body in

sexual intercourse, for example, without having spiritual impact!  Some people have thought they could, but they realize otherwise.
I imagine this concept could be expanded to include other things in some of our lives – maybe even some of the ones listed above, but it is dangerous to call something unclean that God has not called unclean.  Is it important that we are open to God in regards to our bodies, and fully in submission to Him.  If you believe that the Spirit, who dwells in you, is challenging you to take better care of His temple any way – obey!
So, if you are one who thinks what your body does is not connected with your relationship with God, guess again!
Most of us know this to be true, don’t we?
At the same time, check out Romans 14 about how careful we need to be in regards to being considerate to others in our behavior and in assuming that someone else’s behavior is evil sin, unless it is clearly labeled as such by scripture.  This is a tough passage meant to challenge everyone!  Maybe we can talk more about it in the future.  Now, back to tattoos.
Now, regarding those, like Lev 19:28 – about marking oneself with a tattoo.  When you look at these passages, you can see the purpose being that God wanted His people to be set apart – to even look different and behave differently from those around them.
The pagans, as they sometimes still do, for example, cut themselves in honor of the dead, or in supplication of another god (see 1 Kings 18).  Others apparently marked or tattooed their bodies, probably also for religious significance.
God apparently wanted His people to remember that He is in control of things like life and death and identity – not them or some other god – so the final note is “I am the Lord.”  as in “and don’t you forget it”
Now, I am not advocating people getting a tattoo, which I think it folly in the extreme, but it is important to remember 2 things about the Old Testament laws:
1.  They are not all applicable to us.  As Jesus showed Peter in a vision, even the laws of unclean animals no longer rules our behavior.  Do you friends ever eat bacon, sausage, or pork, for example?  They do, however, offer us insight into God’s character and mindset for wise living.  The laws were given to set His people apart and give them a code as a nation to live by.  The commandment to obey father and mother does not promise to give an individual long life, but it promises that the people of Israel will be in the land for a long time, for example.  In fact, check out the verse before the one cited:
Lev 19:27-28 NASU
27 “You shall not round off the side-growth of your heads nor harm the edges of your beard.
28 “You shall not make any cuts in your body for the dead nor make any tattoo marks on yourselves: I am the LORD.
Do any of your friends have extremely long side burns?  Do they ever cut their facial hair?  If they ignore these commands, then they are breaking the law directly connected to the tattoo one.  These were there to set His people apart – which people with long beards and side burns are.
2.  The laws are good for pointing out sin, but not for creating righteous behavior.  Much of Paul’s writings are dedicating to reminding us that Christ is who brings about righteousness, not our behavior.  We surrender our behavior in an effort to worship and express appreciation to him, not in order to become righteous.  Read Romans 7.
Wisdom (and other thoughts)
In regards to tattoos in particular, I think very often getting a tattoo is generally foolish (no, not always), and I think most people know it.  You want proof?
I often encourage young people to “wait until you are 35 to get a tattoo.”  You know what a common response to that is?
“But I might not want to get one when I am 35.”
Exactly, but you will have one.  Right?  Make sure when choosing a tattoo, or whether to get one, to check in with yourself at 35, 55, and 75.
The big tattoo on your forehead is a career choice for the rest of your life… even if it isn’t offensive.
It is generally done in a disregard for the future and a disregard as to what will cause others to stumble.
Though I believe it is not prohibited in any scripture that applies directly to the modern believer, I do think it often generally indicates an arrogant attitude of ownership of oneself.
Finally, it is almost always done without the encouragement of a parent or another authority, for example.  I can tell you that most adults in general see tattoos (especially publicly visible ones) as a sign of immaturity, or as having been done in a phase of immaturity.
Getting a fish or a cross clearly does not mean anything since I have seen many crosses or fish on people whose lives would indicate they are in active rebellion against God.  Though they are cool, and I can sympathize with wanting one, as I have seriously examined them in my life, I would recommend that no one who does not have children of their own should get one.
If a mature adult Christian parent still wanted to get one, after having such insight, I would probably be all for it.  Interesting how rarely that happens though – I wonder why that is?
I am hesitant to write all of this above, however, because I don’t ever want to teach in any way against the law of God.  God’s laws are good and we must seek to figure out how to apply them to our lives presently as believers.
Christ did not abolish them, He fulfilled them through His grace and sacrifice.  Are we willing to sacrifice what we want and desire for Him?  That is the real question.
I am also hesitant because I think tattoos can be cool and can be very redemptive for some people.  So, I do not want to imply a rule about them… maybe just a mature way of asking oneself about them.
Finally, let me note that some Christian kids want to get tattoos of religious symbols in what I think is an odd but interesting variety of rebellion.  I think they want to rebel against the poor and empty version of Christianity that their parents live out, but they do not want to rebel against God.
In an effort to “balance” all that, they do something they know their legalistic parents will hate, but that they think will actually connect them more surely to God.  I think this is often an indication that the youth feels unable to connect with one or both of their parents, but really wants the parents to see that something is wrong.
I would recommend that any parent facing that do some serious soul searching and figure out what it is about their faith that is not passionate, or true, or real enough to inspire their child.
Thoughts?
Chris