It would seem to me that all of the scriptures must fit together in agreement, and we should not ignore any of them, but try to see the harmony of them. I am having trouble understanding how the unregenerate natural man, as described in 1 Cor 2:14, can truly repent of breaking a spiritual law that he cannot discern, and even thinks it to be foolishness. Can you explain this for me?
They come to repentance after hearing the gospel - if they choose to accept Jesus as Lord and Savior of their life. God makes it so they are able to sufficiently understand it - if they're sincere in wanting to understand it. Anyone willfully resisting the gospel, will by their resistance - keep themselves by understanding the gospel. God's Spirit works to draw as many people to Him - save them - as much as is possible, always. That's why God commands everyone everywhere to repent:
Acts 17:30-31
30 And the times of this ignorance God winked at; but now commandeth all men every where to repent:
31 Because he hath appointed a day, in the which he will judge the world in righteousness by that man whom he hath ordained; whereof he hath given assurance unto all men, in that he hath raised him from the dead.
KJV
God calls all people, but most reject Him. He calls them with His Spirit.
Matt 22:14
14 For many are called, but few are chosen.
KJV
One example of one story in which it's clear God's Spirit directly called out to an unbeliever is Saul of Tarsus. He'd been a persecutor of Christians at that point.
Acts 9:4-5
4 And he fell to the earth, and heard a voice saying unto him, Saul, Saul, why persecutest thou me?
5 And he said, Who art thou, Lord? And the Lord said, I am Jesus whom thou persecutest: it is hard for thee to kick against the pricks.
KJV
Also, in the early part of the book of Acts when the Holy Spirit was outpoured - one result was that many got saved through the preaching of the apostles.