The title is a little blunt, but I couldn't quite figure out how to word it.
I'm a history student at a UK university and my main area of interest is early modern Europe. I was having a discussion with another history student about Philip II of Spain. He argued that Philip used religion as a sort of facade to justify his political goals. I disagreed (and my tutor agreed with my side) saying that Philip was deeply pious and religion played a huge role in his life, often guiding his political ambitions, not the other way around.
Nowadays it might not be so difficult to look back and imagine someone use religion as a facade to promote political goals, but I've come to believe that this wasn't the case in the 16th century. God/religion really was a huge part of people's life, from the peasants to the prince. HOWEVER what I don't understand (I admit because I've not studied in depth) is how powerful religions figures like the Borgia Popes (and others) could so blatantly use their position of religious power for their own gain.
My question is if God truly was important to everyone, how could people, even Popes, justify doing unholy things for personal/family gains if they believed they would go to hell for such religious crimes (such as fraud, murder, simony etc).
Oh boy oh boy, a question about Philip II, woo!!!
If I may criticize the way in which you cast your question on Philip II, consider the following sequence of questions:
Was Philip II religiously pious? This is clear, he was very pious.
Would he tolerate religious dissent in his dominions? It depends on which, and at which point in his life. He didn't tolerate any dissent in the Iberian peninsula itself, but he did consider some level of tolerance in the Low Countries. This attitude shifted over time.
Would he cultivate a relationship with foreign leaders who were not Catholic? Yes .... and no! It again depends. When his wife Mary Tudor died without heir, Elizabeth the Protestant came to power in England. Yet for decades Philip continued to treat Elizabeth as a passive ally, in order to keep his sea lanes to the Low Countries clear, and to stop potential French expansion onto England. This is why he supported Elizabeth against Mary the Scot, who was seen as a French puppet.
So in analyzing attitudes, consider that:
Decisions, choices, attitudes do not exist in a vacuum. Philip had to juggle many many issues and often had to make decisions when he was under-informed, mis-informed, and sometimes he had to bluff.
Attitudes change over time. For example, the attitude towards a Protestant England. If we are to ask, would Philip tolerate any religious dissent at the end of his life, the answer is very arguably, not at all. Not after all that happened with the hardening religious tension in the Low Countries, what he saw as betrayal by England, and even more so the many attempts of Protestants to collaborate with the Ottomans and their client states in the Mediterranean.
If I may suggest, the new-ish "Philip II: Imprudent King" by Parker is a fantastic read, as is his oldie-but-goodie paper "Why Did the Dutch Revolt Last Eighty Years?," Trans. Royal Historical Society, vol. 26, December 1976.
Religion is now opposed to secular, something typically private, open to choice, separate from people's working lives. In this period you would find religion to be in everything, a matter of everyday practicality, unable to be separated from economics. A merchant would ask for a priest's blessing of a new ship in the same way you would get insurance for a car. Heresy was not some abstract annoyance, but something which put communities in danger of being in error, and therefore consigned to a real hell with real demons. Likewise, a priest had a job as priest, and an ambitious one could be expected to try to advance in the hierarchy. If he was skillful enough to become a bishop or even pope, he then had command of large assets and appointments of benefices, and it would be a great temptation for him to use them to help his family, and great temptation for his family to approach him for help- that is the consequence of people gaining power, in general.
As to how they would excuse themselves for this, in their own minds: perhaps someone with deeper knowledge of this can cite some specific examples, but I would expect that Pope Alexander would be thinking of himself as having done enough good works to balance out the bad, would confess his sins regularly and be absolved. Maybe he would worry a bit about joining those bad priests and popes in Dante's hell...but maybe not.