As I’ve pointed out, God’s calling, in scripture, is not irresistible.
Scripture doesn’t spend a lot of time discussing the why and wherefore, but Jesus gave several REASONS why some refuse to believe. I doubt his list was exhaustive.
God's general call to all men to repent is indeed resistible, but his effectual calling (his SAVING Grace) is irresistible to all who are saved.
Man's nature is to resist God. Only if God changes your nature can you answer God's call.