At first glance, he seems to be a person who loves people of the races because they have been blessed by gods and are their descendants as well as hate those considered "Demon Lord Worshippers" (since they are turning against God and the races to follow the Demon King).  

In truth, he is a person who uses the "suspicion of being a Demon King Worshipper" to arrest the person/people of suspect of going against the church and it's corrupt actions, tortures them until they confess to false charges, and executes them in the name of God and the church. Basically, he is an unexpected and untrustworthy person who would place suspicion on innocent people.  

He has also deluded himself into believing that he is God who has been given physical form. Along with that, he believes that the torture he brings on people falsely accused as Demon Lord Worshippers isn't "torture" but an act of "bringing salvation" on people who made the mistake of worshiping the Demon Lord and their eventual death is "God (and Saddler) forgiving them and inviting them into heaven". He also believes that removing the unique body parts of demi-humans brings them closer to being a normal proper human; showing signs of demi-human discrimination.