1 Corinthians 2:14

For the natural man is not able to take in the things of the Spirit of God: for they seem foolish to him, and he is not able to have knowledge of them, because such knowledge comes only through the Spirit.

1 Corinthians 1:18

For the word of the cross seems foolish to those who are on the way to destruction; but to us who are on the way to salvation it is the power of God.

Jude 1:19

These are the men who make divisions, natural men, not having the Spirit.

Matthew 13:11-17

And he said to them in answer, To you is given the knowledge of the secrets of the kingdom of heaven, but to them it is not given.

1 Corinthians 15:44

It is planted a natural body; it comes again as a body of the spirit. If there is a natural body, there is equally a body of the spirit.

Matthew 16:23

But he, turning to Peter, said, Get out of my way, Satan: you are a danger to me because your mind is not on the things of God, but on the things of men.

John 3:3-6

Jesus said to him, Truly, I say to you, Without a new birth no man is able to see the kingdom of God.

John 5:44

How is it possible for you to have faith while you take honour one from another and have no desire for the honour which comes from the only God?

John 8:51-52

Truly I say to you, If a man keeps my word he will never see death.

1 Corinthians 15:46

But that which is natural comes before that which is of the spirit.

James 3:15

This wisdom is not from heaven, but is of the earth and the flesh and the Evil One.

Proverbs 14:6

The hater of authority, searching for wisdom, does not get it; but knowledge comes readily to the open-minded man.

John 6:44-45

No man is able to come to me if the Father who sent me does not give him the desire to come: and I will take him up from the dead on the last day.

John 8:43

Why are my words not clear to you? It is because your ears are shut to my teaching.

John 10:20

And a number of them said, He has an evil spirit and is out of his mind; why do you give ear to him?

John 10:26-27

But you have no belief because you are not of my sheep.

John 12:37

But though he had done such a number of signs before them, they still had no belief in him:

John 14:26

But the Helper, the Holy Spirit, whom the Father will send in my name, will be your teacher in all things and will put you in mind of everything I have said to you.

John 15:26

When the Helper comes, whom I will send to you from the Father even the Spirit of true knowledge who comes from the Father--he will give witness about me;

John 16:8-15

And he, when he comes, will make the world conscious of sin, and of righteousness, and of being judged:

Acts 16:14

And a certain woman named Lydia, a trader in purple cloth of the town of Thyatira, and a God-fearing woman, gave ear to us: whose heart the Lord made open to give attention to the things which Paul was saying.

Acts 17:18

And some of those who were supporters of the theories of the Epicureans and the Stoics, had a meeting with him. And some said, What is this talker of foolish words saying? And others, He seems to be a preacher of strange gods: because he was preaching of Jesus and his coming back from the dead.

Acts 17:32

Now on hearing about the coming back from death, some of them made sport of it, but others said, Let us go more fully into this another time.

Acts 18:15

But if it is a question of words or names or of your law, see to it yourselves; I will not be a judge of such things.

Acts 25:19

But had certain questions against him in connection with their religion, and about one Jesus, now dead, who, Paul said, was living.

Acts 26:24-25

And when he made his answer in these words, Festus said in a loud voice, Paul, you are off your head; your great learning has made you unbalanced.

Romans 8:5-8

For those who are living in the way of the flesh give their minds to the things of the flesh, but those who go in the way of the Spirit, to the things of the Spirit.

1 Corinthians 1:23

But we give the good news of Christ on the cross, a hard thing to the Jews, and a foolish thing to the Gentiles;

1 Corinthians 2:12

But we have not the spirit of the world, but the Spirit which comes from God, so that we may have knowledge of the things which are freely given to us by God.

2 Corinthians 4:4-6

Because the god of this world has made blind the minds of those who have not faith, so that the light of the good news of the glory of Christ, who is the image of God, might not be shining on them.

1 John 2:20

And you have the Spirit from the Holy One and you all have knowledge.

1 John 2:27

As for you, the Spirit which he gave you is still in you, and you have no need of any teacher; but as his Spirit gives you teaching about all things, and is true and not false, so keep your hearts in him, through the teaching which he has given you.

1 John 5:20

And we are certain that the Son of God has come, and has given us a clear vision, so that we may see him who is true, and we are in him who is true, in his Son Jesus Christ. He is the true God and eternal life.

Treasury of Scripture Knowledge

Summary

But the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him: neither can he know them, because they are spiritually discerned.

Bible References

Receiveth

Matthew 13:11
And he said to them in answer, To you is given the knowledge of the secrets of the kingdom of heaven, but to them it is not given.
Matthew 16:23
But he, turning to Peter, said, Get out of my way, Satan: you are a danger to me because your mind is not on the things of God, but on the things of men.
John 3:3
Jesus said to him, Truly, I say to you, Without a new birth no man is able to see the kingdom of God.
John 8:43
Why are my words not clear to you? It is because your ears are shut to my teaching.
John 10:26
But you have no belief because you are not of my sheep.
John 12:37
But though he had done such a number of signs before them, they still had no belief in him:
Romans 8:5
For those who are living in the way of the flesh give their minds to the things of the flesh, but those who go in the way of the Spirit, to the things of the Spirit.

The things

1 Corinthians 2:12
But we have not the spirit of the world, but the Spirit which comes from God, so that we may have knowledge of the things which are freely given to us by God.
John 14:26
But the Helper, the Holy Spirit, whom the Father will send in my name, will be your teacher in all things and will put you in mind of everything I have said to you.
John 15:26
When the Helper comes, whom I will send to you from the Father even the Spirit of true knowledge who comes from the Father--he will give witness about me;
John 16:8
And he, when he comes, will make the world conscious of sin, and of righteousness, and of being judged:

They

1 Corinthians 1:18
For the word of the cross seems foolish to those who are on the way to destruction; but to us who are on the way to salvation it is the power of God.
John 8:51
Truly I say to you, If a man keeps my word he will never see death.
John 10:20
And a number of them said, He has an evil spirit and is out of his mind; why do you give ear to him?
Acts 17:18
And some of those who were supporters of the theories of the Epicureans and the Stoics, had a meeting with him. And some said, What is this talker of foolish words saying? And others, He seems to be a preacher of strange gods: because he was preaching of Jesus and his coming back from the dead.
Acts 18:15
But if it is a question of words or names or of your law, see to it yourselves; I will not be a judge of such things.
Acts 25:19
But had certain questions against him in connection with their religion, and about one Jesus, now dead, who, Paul said, was living.
Acts 26:24
And when he made his answer in these words, Festus said in a loud voice, Paul, you are off your head; your great learning has made you unbalanced.

General references

Proverbs 8:9
They are all true to him whose mind is awake, and straightforward to those who get knowledge.
Proverbs 28:5
Evil men have no knowledge of what is right; but those who go after the Lord have knowledge of all things.
Luke 7:23
And a blessing will be on him who has no doubts about me.
John 1:5
And the light goes on shining in the dark; it is not overcome by the dark.

Basic English, produced by Mr C. K. Ogden of the Orthological Institute - public domain