#Morality is subjective and relative. What is good for one is evil for another. A yardstick is required.
Some would use their holy books in that capacity. That is a terrible idea. Such texts are replete with moral and logical errors.
A thread:
The yardstick must be fair for all. To this end, the Golden Rule is the best yardstick. Treat others the way you would be treated. Place others ahead of yourself and your beliefs. Give the respect to others you would expect.
The antithesis of this, selfishness at the expense of others, is the definition of moral crime. It is the root of all evil. The basis of every evil committed by humanity.