To what extent were the policies of Isabella and Ferdinand of Spain motivated by religious considerations?

Religion, during Isabella and Ferdinand's reign was held in extreme high regard; however it is unfair to say that Isabella and Ferdinand's policies were motivated solely by religious issues. The Crown did on occasion, place 'spiritual health' above matters considered to be more mundane and conventional - but I believe that there was a lot more than religious issues responsible for their actions. Isabella was regarded as an extremely religious queen; she viewed religion as …

…nobility's armies and keep them engaged, whilst the crown 'spoon fed' the nobility and then awarded them, in bid to keep them under control and loyal? I believe that religion did play a huge part on the policies of Isabella and Ferdinand; particularly Isabella, however I believe that they were also able to manipulate religious excuses to suit their political, economical and social gain - for instance in the war against the Moors in Granada.