Final answer:
According to tradition, St. James the Greater is believed to be the first to bring Christianity to Spain during the 1st century AD.
Step-by-step explanation:
According to tradition, St. James the Greater is believed to be the first to bring Christianity to Spain. It is said that he preached in the region during the 1st century AD. St. James is also known as the patron saint of Spain and the famous pilgrimage route, the Camino de Santiago, is dedicated to him.