1 Corinthians 2:14

But the natural man does not perceive the things of the Spirit of God, for they are foolishness unto him; neither can he understand them because they are spiritually discerned.

1 Corinthians 1:18

For the word of the cross is foolishness to those that perish, but unto us who are saved, it is the power of God.

Jude 1:19

These are those who make divisions, and are as animals, not having the Spirit.

Matthew 13:11-17

He answered and said unto them, Because it is given unto you to know the mysteries of the kingdom of the heavens, but to them it is not given.

1 Corinthians 15:44

it is sown a natural body, it shall be raised a spiritual body. There is a natural body, and there is a spiritual body.

Matthew 16:23

But he turned and said unto Peter, Remove thyself from before me, Satan; thou art an offence unto me, for thou dost not understand that which is of God, but that which is of men.

John 3:3-6

Jesus answered and said unto him, Verily, verily, I say unto thee, Except a person be born again from above, he cannot see the kingdom of God.

John 5:44

How can ye believe, who take glory one from another, and seek not the glory that comes only from God?

John 8:51-52

Verily, verily, I say unto you, If anyone keeps my word, he shall not see death forever.

1 Corinthians 15:46

Howbeit the spiritual is not first, but the natural; and afterward, that which is spiritual.

James 3:15

This wisdom is not that which descends from above, but is earthly, natural, diabolical.

Proverbs 14:6

The scorner sought wisdom and found it not, but wisdom comes easy unto him that understands.

John 6:44-45

No one can come to me unless the Father who has sent me draws him, and I will raise him up in the last day.

John 8:43

Why do ye not understand my speech? even because ye cannot hear my word.

John 10:20

And many of them said, He has a demon and is beside himself; why do ye hear him?

John 10:26-27

But ye believe not because ye are not of my sheep, as I said unto you.

John 12:37

But although he had done so many signs before them, yet they did not believe in him,

John 14:26

But the Comforter, which is the Holy Spirit, whom the Father will send in my name, he shall teach you all things and bring to your remembrance all the things that I have said unto you.

John 15:26

But when the Comforter is come, whom I will send unto you from the Father, even the Spirit of truth, which proceeds from the Father, he shall testify of me;

John 16:8-15

And when he is come, he will reprove the world of sin and of righteousness and of judgment:

Acts 16:14

Then a certain woman named Lydia, a seller of purple, of the city of Thyatira, who feared God, heard us, whose heart the Lord opened that she attended unto the things which were spoken by Paul.

Acts 17:18

Then certain philosophers of the Epicureans and of the Stoics encountered him. And some said, What will this babbler say? others, He seems to be a setter forth of new gods, because he preached unto them Jesus and the resurrection.

Acts 17:32

And when they heard of the resurrection of the dead, some mocked; and others said, We will hear thee again of this matter.

Acts 18:15

but if it is a question of words and names and of your law, look ye to it, for I will be no judge of such matters.

Acts 25:19

but had certain questions against him of their own superstition, and of one Jesus, who was dead, whom Paul affirmed to be alive.

Acts 26:24-25

And as he spoke these things and answered for himself, Festus said with a loud voice, Paul, thou art beside thyself; much learning doth make thee mad.

Romans 8:5-8

For those that are according to the flesh know the things that are of the flesh; but those that are according to the Spirit, the things that are of the Spirit.

1 Corinthians 1:23

but we preach Christ crucified, , unto the Jews a stumblingblock and unto the Gentiles foolishness;

1 Corinthians 2:12

Now we have not received the spirit of the world, but the Spirit which is of God, that we might know the things that God has given us.

2 Corinthians 4:4-6

In whom the god of this age has blinded the understanding of those who do not believe, that the light of the gospel of the glory of the Christ, who is the image of God, should not shine in them.

1 John 2:20

But ye have the anointing of the Holy One, and ye know all things.

1 John 2:27

But the anointing which ye have received of him abides in you, and ye do not need that anyone teach you; but as the same anointing teaches you of all things and is truth, and is no lie; and even as it has taught you, abide ye in him.

1 John 5:20

But we know that the Son of God is come and has given us understanding, that we may know him that is true, and we are in him that is true, even in his Son Jesus Christ. This 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
He answered and said unto them, Because it is given unto you to know the mysteries of the kingdom of the heavens, but to them it is not given.
Matthew 16:23
But he turned and said unto Peter, Remove thyself from before me, Satan; thou art an offence unto me, for thou dost not understand that which is of God, but that which is of men.
John 3:3
Jesus answered and said unto him, Verily, verily, I say unto thee, Except a person be born again from above, he cannot see the kingdom of God.
John 8:43
Why do ye not understand my speech? even because ye cannot hear my word.
John 10:26
But ye believe not because ye are not of my sheep, as I said unto you.
John 12:37
But although he had done so many signs before them, yet they did not believe in him,
Romans 8:5
For those that are according to the flesh know the things that are of the flesh; but those that are according to the Spirit, the things that are of the Spirit.

The things

1 Corinthians 2:12
Now we have not received the spirit of the world, but the Spirit which is of God, that we might know the things that God has given us.
John 14:26
But the Comforter, which is the Holy Spirit, whom the Father will send in my name, he shall teach you all things and bring to your remembrance all the things that I have said unto you.
John 15:26
But when the Comforter is come, whom I will send unto you from the Father, even the Spirit of truth, which proceeds from the Father, he shall testify of me;
John 16:8
And when he is come, he will reprove the world of sin and of righteousness and of judgment:

They

1 Corinthians 1:18
For the word of the cross is foolishness to those that perish, but unto us who are saved, it is the power of God.
John 8:51
Verily, verily, I say unto you, If anyone keeps my word, he shall not see death forever.
John 10:20
And many of them said, He has a demon and is beside himself; why do ye hear him?
Acts 17:18
Then certain philosophers of the Epicureans and of the Stoics encountered him. And some said, What will this babbler say? others, He seems to be a setter forth of new gods, because he preached unto them Jesus and the resurrection.
Acts 18:15
but if it is a question of words and names and of your law, look ye to it, for I will be no judge of such matters.
Acts 25:19
but had certain questions against him of their own superstition, and of one Jesus, who was dead, whom Paul affirmed to be alive.
Acts 26:24
And as he spoke these things and answered for himself, Festus said with a loud voice, Paul, thou art beside thyself; much learning doth make thee mad.

General references

Proverbs 8:9
They are all plain to him that understands and right to those that have found wisdom.
Proverbs 28:5
Evil men do not understand judgment, but those that seek the LORD understand all things.
Luke 7:23
and blessed is whoever shall not be offended in me.
John 1:5
And the light shines in the darkness, and the darkness apprehended it not.