How to choose between what's right and wrong

Every one has grown with different types of life, you can not force someone that has been happy all their life to think the same as someone that has been sad all their life. What I mean is we all grew with different mind sets, and the people that sorruond us changes and have a huge impact in our decisions. If you went to a catholic school you may have different believes on what is wrong or right from a person that went to a public school. Both schools are good, but they teach different values and that influences kids and what they think. Lets take as an example someone that has this idea of getting a tattoo, this person isn't catholic or in another religion for him this decision does not look wrong; in the other hand, his mom is catholic and she thinks that is a wrong idea, and that in the bible it says that is a sin. You get how your believes and how you were raised influences your decision? There will always be someone that does not agree with what you think, of what is wrong or right to you, we all grew in different homes with different perspectives and that influences on what you think is right or wrong. So we get to choose what is wrong or right for us, and we should not change how we think because people does not agree, we all have different ideas of how things can be based on our decision. Maybe there isn't an absolute right or wrong.