If anyone...

"But you are not in the flesh but in the Spirit, if indeed the Spirit of God dwells in you. Now if anyone does not have the Spirit of Christ, he is not His." Romans 8.9

Even before Paul revealed that, Jesus had already said: "... unless one is born again, he cannot SEE the kingdom of God.” John 3:3;
Then he said: "If anyone does not abide in Me, he is cast out as a branch and is withered..." John 15.6.
Finally, "And anyone not found written in the Book of Life was cast into the lake of fire." Revelation 20.15.
Do these verses require interpretation?

MANY BELIEVERS, VERY FEW CHRISTIANS

Most assuredly, I say to you, unless one is born again, he cannot see the kingdom of God.Most assuredly, I say to you, unless one is born of water and the Spirit, he cannot enter the kingdom of God.       John 3.3-5

Only those who are born again can SEE the Kingdom of the Spirit of God.
Only those who are born of water and the Spirit can ENTER the Kingdom of the Spirit of God.
This is why many are believers; however, very few are Christians.

Emptiness of soul

"The poor shall eat and be satisfied; those who seek Him will praise the LORD. Let your heart live forever! ."

Psalms 22: 26

Emptiness of the heart can only be filled with the joy of the new birth. It's the exclusive work of the Holy Spirit, nevertheless, for it to happen, there must be a desire from all your heart, mind, and soul to receive it.

Confirmation

"The Spirit Himself bears witness with our spirit that we are children of God..."

Romans 8.16

Those who are born of God have the most absolute assurance that they're children of God because the Holy Spirit Himself confirms this within them. This is the greatest Christian glory.

Have Spirit

"But you are not in the flesh but in the Spirit, if indeed the Spirit of God dwells in you. Now if anyone does not have the Spirit of Christ, he is not His." Romans 8:9

When passions of the flesh are abandoned, doors are opened for the Holy Spirit to bear a new creature in you. Once you're born of God, you have His DNA -- that's when you begin to think and behave like Him.

Corrupt

"The heart is deceitful above all things, and desperately wicked; Who can know it?" Jeremiah 17:9

If there's no new birth, there's no solution for the corrupt and deceitful heart -- it'll lead you to eternal death. Even for those of the Christian faith.

Hated

"I have given them Your word; and the world has hated them because they are not of the world, just as I am not of the world." John 17:14

The Word of God transformed us into new creatures, fulfilled in happiness and goodness. For this reason, those who are still in their old nature, who don't know the One responsible for our changes, hate us.