Calvinists believe natural men have no intelligence, knowledge, ability to communicate with God, or ability to humble themselves before God at the enlightenment of the Holy Ghost. They think unsaved men are like zombies without emotion or brains, which is stupid.
Genesis 4
9 And the Lord said unto Cain, Where is Abel thy brother? And he said, I know not: Am I my brother's keeper?
10 And he said, What hast thou done? the voice of thy brother's blood crieth unto me from the ground.
11 And now art thou cursed from the earth, which hath opened her mouth to receive thy brother's blood from thy hand;
12 When thou tillest the ground, it shall not henceforth yield unto thee her strength; a fugitive and a vagabond shalt thou be in the earth.
13 And Cain said unto the Lord, My punishment is greater than I can bear.
Sinners in the OT were required to offer yearly sacrifices for their sins in order to have those sins covered. God did not offer those sacrifices for them. They were required to offer the sacrifices for themselves of their own free will.
Leviticus 1
1 And the Lord called unto Moses, and spake unto him out of the tabernacle of the congregation, saying,
2 Speak unto the children of Israel, and say unto them, If any man of you bring an offering unto the Lord, ye shall bring your offering of the cattle, even of the herd, and of the flock.
3 If his offering be a burnt sacrifice of the herd, let him offer a male without blemish: he shall offer it of his own voluntary will at the door of the tabernacle of the congregation before the Lord.
God passes over sins of ignorance, but not sins committed willfully after the sinner has been enlightened by the Holy Ghost.
Acts 17:30
And the times of this ignorance God winked at; but now commandeth all men every where to repent:
Romans 1:20
For the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, even his eternal power and Godhead; so that they are without excuse: