"A gentleman becomes a gentleman, and a villain becomes a villain." What does this mean?

Probably this sentence often appears in calligraphy. In fact, you can literally understand: appropriate, appropriate. A gentleman should be able to describe his character. A character that a gentleman needs is to be decent when doing things or getting along with others, so that people around him feel comfortable. You can refer to the following information, which is about the difference between a gentleman and a villain and the standard of a gentleman, covering what I said to you.