This is not even on the subject, The natural man cannot even comprehend spiritual things much less reject HIM
To show that natural men can be held accountable for having known the truth yet rejecting it I give you:
2 Peter 2:20-22
King James Version (KJV)
20 For if after they have escaped the pollutions of the world through the knowledge of the Lord and Saviour Jesus Christ, they are again entangled therein, and overcome, the latter end is worse with them than the beginning.
21 For it had been better for them not to have known the way of righteousness, than, after they have known it, to turn from the holy commandment delivered unto them.
22 But it is happened unto them according to the true proverb, The dog is turned to his own vomit again; and the sow that was washed to her wallowing in the mire.
Do not, as many do, mistake these for born again Christians, because they are identified as false teachers and the New Testament equivalent of false prophets in the Old Testament, who were not believers either:
2 Peter 2
King James Version (KJV)
2 But there were false prophets also among the people, even as there shall be false teachers among you, who privily shall bring in damnable heresies, even denying the Lord that bought them, and bring upon themselves swift destruction.
And if you read this chapter, and Jude, you will see they were always destined for Hell.
Yet they had received the truth, and turned from it.
Another instance of those who have received the truth is seen in the passage we looked at earlier:
Hebrews 10:26-29
King James Version (KJV)
26 For if we sin wilfully after that we have received the knowledge of the truth, there remaineth no more sacrifice for sins,
27 But a certain fearful looking for of judgment and fiery indignation, which shall devour the adversaries.
28 He that despised Moses' law died without mercy under two or three witnesses:
29 Of how much sorer punishment, suppose ye, shall he be thought worthy, who hath trodden under foot the Son of God, and hath counted the blood of the covenant, wherewith he was sanctified, an unholy thing, and hath done despite unto the Spirit of grace?
Note that they have "done despite unto the Spirit of Grace," or in other words, rejected the ministry of God in revealing the truth to them.
They have received the truth, but rejected it, and their punishment will be worse than those who rejected the Covenant of Law.
Again, this passage is thought by many to refer to born again Christians, but, the fact is, those who are born again are made perfect/complete in regards to remission of sins forever, and the Writer uses the identical statement to show those sanctified by the blood of Christ need not have sacrifice offered up for their sins ever...
Hebrews 10:15-18
King James Version (KJV)
15 Whereof the Holy Ghost also is a witness to us: for after that he had said before,
16 This is the covenant that I will make with them after those days, saith the Lord, I will put my laws into their hearts, and in their minds will I write them;
17 And their sins and iniquities will I remember no more.
18 Now where remission of these is, there is no more offering for sin.
Two different contexts between the two, and two different meanings:
Hebrews 10:26
King James Version (KJV)
26 For if we sin wilfully after that we have received the knowledge of the truth, there remaineth no more sacrifice for sins,
There is no more sacrifice for those made perfect, and there is no more sacrifice for those who reject the only sacrifice by which they can be saved.
So yes, the natural man can be enlightened, you are simply confusing that with the concept that natural man has within his own capacity the ability to understand the spritiual things of God, and thereby be saved.
That is what Paul is stating is not possible.
Really leaving this time, so again...have a blessed day.
God bless.