Sánchez said in a (roughly translated) 2014 interview:
I am an atheist and I believe that religion should not be in the classrooms, it has to be in the churches, in the classrooms you have to form citizenship, not people with religious beliefs, that corresponds to the private sphere.
His godless oath today also reflected that mentality:
I promise by my conscience and honor to faithfully fulfill the obligations of the office of President of the Government with loyalty to the King, and to keep and enforce the Constitution as the fundamental norm of the State, Sánchez said.
No to god but yes to the monarch who is the monarch by divine grace. A bit of a contradiction!
Monarchs are mostly nothing more than figureheads anymore, so I think he's safe on that count.
@EricJones overpaid and useless
Honestly, I had never asked anyone if they are an atheist. I am not looking for company or heroes, that includes politicians from anywhere.