Once it becomes clear to the believer that the source of the infidel’s blasphemies are the product of false indoctrination,
Depends on what you mean by indoctrination. Under certain definitions, not all heresies are created by indoctrination.
he should immediately call into question the legitimacy of his own beliefs, which were bestowed upon him by the very same process that the infidel acquired his own falsehoods.
There is an assumption here that the believer acquired his beliefs through the same way as the infidel. This is not always the case.
The infidel’s scriptures, proofs, miracles, prophets, commandments, rituals, and gods, are no less vivid or absolute to him than the believer’s.
Once one realizes that the very nature of religious beliefs are solely dependent on the subjective nature of one’s own experience and indoctrination, it becomes clear that no deity could forge a system in which infidels (who make up the majority of humans by any religion’s standard) are expected to accept his divinity. Furthermore, he cannot credit those who worship him due to the fortuitous circumstances he conferred to them. Therefore the infidel is not worthy of punishment and the believer not worthy of reward. This is the paradox that every theist must confront.
That would be true, if it is only by experience that we know something to be true. However, we can also know true and falsity through reason and virtually all humans are capable of employing reason similarly effectively. Therefore, it is through reason that all men can come to understand what is true, and what is false.
To say otherwise is to resign oneself completely to epistemological relativism. But this is foolish. A math teacher does not say, the method this child employed to get the wrong answer is no less vivid to him, than the method to get the right answer is to me, therefore, the very nature of mathematics is solely dependent on the subjective nature of one’s own experience. One recognizes that there is an objectively right answer to a math problem and an objectively wrong one. As it is with math, so it is with everything else.