You have a really cartoonish view on this. They were not killed because it made God angry. You have to put context on it.
You have to understand that religion was really important (maybe the most important thing) for the people of that period, and you have to know that their religion was threatened for centuries inside their own borders, you have to know about "La reconquista".
In a time of period were your territory was just regained from Moors after centuries of occupation and threatens to your life and beliefs. The only logical move was to identify those who were still Moors in the shadows, from their point of view they were the remains of the invaders they were still dangerous.
You have to know about the kind of punishments for the law breakers (not only religion laws) on that period of time, you have to know that the inquisition was the organization that investigated the cases to identify those who were false conversions (those who were still a threaten from their point of view), then when someone was found guilty for breaking their laws the state was responsable for imparting justice, their justice is very different from today's justice, we have learned a lot, but you can't properly understand their actions if you don't understand the context.