How to Deal with Moral Differences
The first way is to believe there are no morally right or wrong viewpoints. The moral issue is just a cultural game and neither your opinions or mine matters.
Therefore there is no right or wrong. This view is called moral nihilism.
Related to this idea is moral skepticism, which holds that we can’t know any moral truths, and moral subjectivism, which holds that moral views are merely inner states in a person and that they can’t be compared to the inner states of another person. However believing in the above solves no problems, if nobody is right and nobody is wrong.
The second way is to believe that there is no universal truth, that each culture has its own set of rules that are valid and apply to that culture, they don’t interfere with our rules and we don’t interfere with theirs, this is called ethical relativism. This belief is viewed as an attitude of tolerance. This belief solves conflicts in the idea that whatever the majority deems to be the moral rule is the rule to follow.
The third belief is that deep down in spite of all the cultures differences we call all still agree on a certain moral basics, that people everywhere have basically the same human nature but that we just adapt it into our environment, this idea is called Soft Universalism. Universalism because it perceives that there are some universal moral rules; soft because it is not as radical as hard universalism. This belief can solve problems because its main goal is to seek common ground beneath the variety of opinions and mores.
The fourth belief is called hard universalism, this is the absolute opposite of moral nihilism stating that there is only one universal moral code. This belief solves problems with hard evidence and reason.

Problems with Ethical Relativism:
(1) No Criticism or Praise of Other