Morals are nothing more than “rules for right living” – in the particular culture.
Some people understand these rules and have internalized them to an extent that they don’t need to query every action (or potential reaction) in a situation to decide on what to do: they do the thing that they have programmed themselves to do.
The rules sometimes change depending on culture. So if you’re a new person (an infant or small child) or new to the culture (an alien with no prior training), then it’s very likely that you’ll just do what you want, as most small children do until they “learn better”, or you’ll operate under whatever rules you have been used to in your prior culture, which is one reason we often consider new immigrants to be funny (at best) on a sliding scale to “dangerous” and “bad”. By their rules, their actions may be “moral”.
On the other hand, some people attempt to determine (or enforce) what they think are or should be “universal” rules for right living. “The Golden Rule” is often held as such a model. But that fails in some cultures where “others” may not be equal to oneself, such as women, people from other sects or entirely other religions, people of lower caste, etc.
So one thing that you must do before you can even ask this question in a serious way is to define what “good” is. Some of the ideals that we hold in the secular West, for example, including some of our very highest ideals: freedom to worship (or not) as we choose, freedom to speak as our conscience dictates, equality among all, are some of the things that make us “bad” in other cultures.
“Good” and “bad” don’t exist as absolute values. Or, put another way, if good and bad are absolutes, then much of the world, in attempting to be “good” by the lights of their culture are being bad and worse, the harder they try. How do you tell who is who, except by the yardstick of your own culture?