The official religion in Spain is Roman Catholic. Where did they get this religion? Of course from Rome. When the Roman Empire was also developing as a strong nation, they also have spread the Catholicism to their neighboring countries and this is how Spain was colonized by the religion. The Spain then become a Catholic country following all the teachings of the Roman Catholic. Although the nation is filled with many gods, they came to bow down to Roman Catholicism which is also filled with many gods.
There are many feast that they celebrate in accordance with the teaching of RC. These teachings are not found in Christian Bible. Still, many people celebrate them. When the Roman Catholic was ruling the Roman Empire, there was no religious tolerance. All have to obey RC. Unless obeyed, they are executed through the Inquisition. They did not spare a soul when it comes to religious aspect. In this way, RC kept its power and many were forced to obey their teachings.
However, there were some who died due to resistance. Even to the point of death, they never adhere to the teachings of the RC. Even if people see what the RC had done in the past, they will always stick to the RC. Pope John Paul, before he died, asked an apology for all the crimes that the Catholicism had committed and was buried down in history. The Spanish country took a leading role to spread RC in all the world, as a result, many nations come to become the members of the Roman Catholics.