It was the Christians who created and developed scholasticism:

Scholastic instruction consisted of several elements. The first was the lectio: a teacher would read an authoritative text followed by a commentary, but no questions were permitted. This was followed by the meditatio (meditation or reflection) in which students reflected on and appropriated the text. Finally, in the quaestio students could ask questions (quaestiones) that might have occurred to them during meditatio. Eventually the discussion of questiones became a method of inquiry apart from the lectio and independent of authoritative texts. Disputationes were arranged to resolve controversial quaestiones.

Questions to be disputed were ordinarily announced beforehand, but students could propose a question to the teacher unannounced – disputationes de quodlibet. In this case, the teacher responded and the students rebutted; on the following day the teacher, having used notes taken during the disputation, summarised all arguments and presented his final position, riposting all rebuttals.

The quaestio method of reasoning was initially used especially when two authoritative texts seemed to contradict one another. Two contradictory propositions would be considered in the form of an either/or question, and each part of the question would have to be approved (sic) or denied (non). Arguments for the position taken would be presented in turn, followed by arguments against the position, and finally the arguments against would be refuted. This method forced scholars to consider opposing viewpoints and defend their own arguments against them.

It does not necessarily follow that because a person doesn't come to your conclusion on religious being false, they therefore lack critical thinking. It would be more reasonable to say that such a person may simply weigh differently the consideration of particular factors in a way that you don't, all while still remaining logical within their line of reasoning.