There is only one direct reference to tattoos in the Bible where the word "tattoo" is used in most English translations. (Leviticus 19:28). We know from that verse that God prohibited tattoos before the New Covenant. Why did God tell the Israelites not to have tattoos if it is okay for people to have them? The Egyptians especially would make deep gashes in their arms, legs, and faces out of respect for the dead and as an offering to the pagan gods they worshipped. Tattoos were also connected to names of idols therefore. God told the Israelites not to have tattoos because they were connected to names of idols who presided over death according to pagan belief.
The closest thing to a tattoo in the modern sense mentioned in the Bible is the mark of the beast that will be given out by the Antichrist's worldwide government during the last half of the Tribulation. That might not be a tattoo like what we are used to even then. It could be some modern technology like you a computer microchip implanted under the skin that produces an image on the hand or forehead. Or it could be something else. The Greek word used for "mark" in the "mark of the beast" verses in Revelation are the closest thing to a tattoo reference in the New Testament though (Revelation 13:16-18; 14:9-11; 16:2; 19:20; 20:4).Something similar to a tattoo is mentioned as a mark or seal given by God not to harm those who marked or sealed to protect them when others were being judged, punished, and even killed for sin (Genesis 4:15; Ezekiel 9:4-6). Other places where God mentions tattoos in a positive light are Isaiah 49:16 and Deuteronomy 11:18-19.
We can be comfortable with having tattoos today as long as we are not imitating the same practices of these ancient pagan societies. It is biblically permissible for people to have tattoos unless it is for a pagan reason listed above or unless you have a tattoo of something that does not glorify God. Jesus summed up the entire intent of the law in Matthew 22:34-40. Jesus said we are fulfilling and obeying the whole Law when we love God with all our heart, soul, mind, and intellect and love others like we love ourselves. The rest of the Bible's commands show us how to love properly because the word and idea of love sometimes gets altered to mean things it really does not mean. That is why there should be no problem with getting tattoo(s) if they are glorifying God.