We've discussed the possible referent of 2 Cor. 4:4. I still believe it's Satan, whereas some argue that Jehovah (YHWH) is the god of this age (world). Let's assume that Paul is referring to Satan. The verse states that the god of this world blinds the minds of the unbelievers. I used to wonder how Jehovah could allow Satan to blind someone's mind from the good news about the Christ. How can God punish someone who does not accept the truth, if he allowed Satan to blind their minds?
I've since learned that Satan can only blind the minds of those, who do not love divine truth. Paul writes:
"And for this cause God sendeth them a working of error, that they should believe a lie: that they all might be judged who believed not the truth, but had pleasure in unrighteousness" (2 Thessalonians 2:11-12 ASV).
Jehovah allows the desires of their hearts to be fulfilled, in accordance with their free choice.