Pagan is any person or thing that is not related to baptism from the point of view of Judaism, Christianity and Islam, but which follows and adopts rituals of polytheistic religions.
The pagan person is the one who follows the paganism, a term used to refer to the customs and traditions of shamanism, pantheism, animism and polytheism, that is, the belief in multiple gods.
The current concept of the pagan individual and paganism, in general, was created from the perspective of monotheism (belief in a single God), especially the Christian.
According to the Bible, the pagan is described as one who does not worship the true God, but rather "false gods" who lead people astray into a path of sin.
Learn more about Polytheism.
Also according to Christian precepts, pagans are considered heretics, because they question and do not believe in the Holy Scriptures and in other dogmas preached by Christian doctrines.
All worship and praise to the elements of nature or to figures that are unrelated to the Christian God are considered pagan rituals, like Halloween and the Day of the Dead, for example.
It is worth noting that for Christians, Jews and Muslims, after Christ's passage on Earth, they are not treated as pagans, but rather as infidels. Jews before Christ are not considered pagans or infidels, however, they do not have the right to go to Heaven, much less to Hell.
See also the meaning of Heretic.
Etymologically, the word "pagan" originated from the Latin pagan, which means "village", meaning a person who lives in a rustic village. From the fourth century, however, this term came to be used by Christians to refer to individuals who still believed in the ancient Roman gods. In this last sense, the use of the word pagan was seen as pejorative.