That one sentence is the single best definition of orthodoxy that I have ever heard. All of their reasoning is geared toward simultaneously upholding it and denying it. Their highest prerogative is to retain the substance of this thought while changing its form. Imagine a professor standing before the class and writing Ingersoll’s quote on the blackboard. Then imagine he added the words “But God is all-wise and perfectly just”, and then told his students “Now, go figure out how this could be.” The result would be Christian orthodoxy.