Spiritual blindness. The god of this age has blinded their minds from the truth. It takes a genuine miracle to rescue a person from the bondage of Romanism.
God opens the minds of who He will. I certainly don’t understand and have to admit to getting frustrated at why He doesn’t open the minds of some. I think to myself “it’s right there in front of them Lord, why don’t they see?” Thankfully He knows better than I and His ways are above my ways.