Challenge to Christian belief: Doxastic Psychology and the Holy Spirit

If our beliefs ground our actions (at least, if our morally significant beliefs ground our morally significant actions), and if God wants us to perform good actions and refrain from sin, then God wants us to hold good beliefs.

There is this idea out there (Travis Dumsday argues this in a paper) that God deliberately hides so as to reduce the culpability in those who do not believe in God. There are so many problems with this idea that it might just be the worst thesis I've seen in a philosophy paper.

One of many reasons why this thesis is hopeless is because of doxastic psychology. God knows that people act according to their beliefs. By withholding evidence of His existence, God causes, or allows, non-belief. Non-belief causes sin. By transferability of causation, if A causes B and B causes C, then A causes C. (We accept this all the time. If I caused my child's lack of access to food, and my child's lack of access to food causes my child to die, then I caused my child to die.) So if God causes non-belief, and if non-belief causes belief-based sin, then God causes belief-based sin (which is all sin, at least all sin that has any chance of having moral significance).