Not necessarily. How things are done in a manhwa can vary greatly. It could be similar in some cases, but different in others due to artistic choices, story direction, and audience preferences.
Study successful manhwa works. Understand their storytelling techniques, art styles, and character development. That can give you ideas on how to do it better.
Angels tell the Christmas story through various ways. In the Bible, an angel appeared to Mary to tell her she would give birth to Jesus. Then, an angel also announced the good news to the shepherds in the fields. They might convey the story with their heavenly voices, full of joy and wonder, and their appearance which is often described as bright and glorious, catching people's attention and making them listen to the important message of the birth of the Savior.
Well, I think it depends. Sometimes the portrayal of ghosts in manhwa is so imaginative that it's hard to take it seriously. But in some cases, they can add an element of mystery and excitement. So, I'm kind of on the fence about believing in them.