A tattoo is a permanent modification of the skin by using ink to create images. The only clear reference to tattoos in the Bible is found in the Old Testament law.
Do not cut your bodies for the dead or put tattoo marks on yourselves. I am the Lord. Leviticus 19:28
This is a clear command for the Israelites which, based on the context of the chapter, appears to be based on idolatry. The Israelites are forbidden from practices which surrounding nations used in their idol worship. Other similar practices prohibited in Leviticus 19 include divination, omens and mediums.
Other, less clear references, which may concern tattoos include Isaiah talking about the outpouring of God’s Spirit, and a vision of Jesus’ return in Revelation.
Some will say, ‘I belong to the Lord’; others will call themselves by the name of Jacob; still others will write on their hand, ‘The Lord’s,’ and will take the name Israel. Isaiah 44:5
He is dressed in a robe dipped in blood, and his name is the Word of God. The armies of heaven were following him, riding on white horses and dressed in fine linen, white and clean. Coming out of his mouth is a sharp sword with which to strike down the nations. “He will rule them with an iron scepter.” He treads the winepress of the fury of the wrath of God Almighty. On his robe and on his thigh he has this name written: king of kings and lord of lords. Revelation 19:13-16
The Bible does not necessarily forbid all tattoos for Christians. However, a Christian should think carefully about what a tattoo communicates to others, especially with unknown and historical symbols which may be connected to idol worship. Different cultures and contexts will interpret the presence of tattoos in different ways and the Christian should be considerate of that.
Paul’s teaching about different opinions on eating sacrificial meat are helpful.
Therefore let us stop passing judgment on one another. Instead, make up your mind not to put any stumbling block or obstacle in the way of a brother or sister. I am convinced, being fully persuaded in the Lord Jesus, that nothing is unclean in itself. But if anyone regards something as unclean, then for that person it is unclean. If your brother or sister is distressed because of what you eat, you are no longer acting in love. Do not by your eating destroy someone for whom Christ died. Therefore do not let what you know is good be spoken of as evil. For the kingdom of God is not a matter of eating and drinking, but of righteousness, peace and joy in the Holy Spirit, because anyone who serves Christ in this way is pleasing to God and receives human approval. Let us therefore make every effort to do what leads to peace and to mutual edification. Do not destroy the work of God for the sake of food. All food is clean, but it is wrong for a person to eat anything that causes someone else to stumble. It is better not to eat meat or drink wine or to do anything else that will cause your brother or sister to fall. Romans 14:13-21
A loving attitude in disputable matters will take into account their effect on others. A Christian may be free to get a tattoo but should think about motivation, culture and the context of the tattoo before proceeding.