I think unfortunately, if the church had stayed faithful only to the good ideas of the past (commandments, life, liberty, property, etc.), it would have disappeared very quickly because these are very idealistic principles by nature that can be easily corrupted by bad and greedy people (the absolute majority of people). In a way, the infection with terribly wrong ideas was a necessary adaption to reality, which was very effective as we are still discussing this 2k years down the road.

Also regarding the role of the church as a symmetry breaker in the political system if the medieval: It could be true for later times, but in many cases the church was the origin of this centralization and, hence, the power. The Vikings (and later also the Normans) adopted Christianity to strengthen their power, for example, in Kievan Rus‘ and Normandy.

Thanks for mentioning the book. I will take a look at it.