|Medieval " Wikipedia": The Bible|
Imagine a world without Google, Wikipedia, encyclopedias, libraries, in fact without books and those only for the tiny educated elite. There you have it- a world with just one legitimate source of knowledge, the Bible. Everything that was known or could be known was contained in this one book and anything new that came up had to be understood in terms of it. This is the medieval mind-set, the way that people thought at the time of Columbus' journeys and the Spanish Conquest of the New World that followed. There were some like Copernicus and Galileo who were independent thinkers, but they were branded as heretics by the Church.
This was not a time that accorded equal status to all religions. Christianity to them was the crown of God's plan for mankind and the apocalyptic views prevalent at the time stated that all mankind must be converted to Christianity before the second coming of Christ and the end-times when all would be set right in the reign of Jesus the messiah. The Spanish had been successful in this venture on their own peninsula in the reconquista and with the final expulsion of the Jews in 1492. Completely ridding the land of Muslims was a work in process. It is no wonder that with the discovery of new unconverted peoples in the Americas that they passionately pursued their policy of spiritual conquest. As they understood it, it was their holy mission.
Unknown to most of us are the apocalyptic writings of Christopher Columbus, The Book of Prophecies, written after his third voyage. In it he justified his voyages in terms of the role they played in fulfilling pre-conditions for the second coming of Christ, including the spreading of Christianity throughout the world and the finding of the Garden of Eden in the Americas. This is not the Columbus most of us encountered in grade school who "discovered America". This is the Columbus driven by the religious ideology of his time. Remember, his ships all had crosses on the sails and this was not for "X marks the spot". They were the symbols of the faith that drove his world.
Understanding the mindset of the times, it is easier to be less judgmental about the Conquistadors and their religious arm, the Franciscan, Dominican, Augustinian and other friars (men in the religious orders) who accompanied them. They were doing what they believed was the correct thing- saving the world. This is the imperative they were fulfilling even if we, centuries later, disagree with their methods.