No one should think that just because they accepted Jesus as their Lord, they already belong to the Kingdom of God. A little bit of intelligent faith is all that is needed to understand this.

How can someone born of the flesh (biological parents alone) inherit the Kingdom of God without having been involved with the Spirit of God? Is it possible for flesh and blood to inherit the Kingdom of God? The Holy Scriptures teaches:

Now this I say, brethren, that flesh and blood cannot inherit the kingdom of God; nor does corruption inherit incorruption. 1 Corinthians 15:50

The Lord Jesus commanded us to preach the Gospel of the Kingdom of God and provided His Spirit to allow us to meet the requirements of the new birth (born of the Holy Spirit), so that in His Spirit we could live in His Kingdom. Is it possible for someone who is carnal to submit to the discipline of spiritual laws? Is it possible for someone who lives a disorderly life to submit themselves to the Kingdom of Discipline?

The most important commandments of the Law of the Kingdom of God are: Justice, Mercy and Faith. Without the practice of these three, there is no way to enter the Kingdom of God. This is precisely why the Lord sent the Holy Spirit: to transform the life of those who want it.

In paraphrasing, the Lord Jesus said to a religious leader: Boy, it is of no use being religious if you are not born again.

Most assuredly, I say to you, unless one is born again, he cannot see the kingdom of God.” Nicodemus said to Him, “How can a man be born when he is old? Can he enter a second time into his mother’s womb and be born? John 3:3-4

Nicodemus showed that he had not understood anything about the new birth. So:

Most assuredly, I say to you, unless one is born of water and the Spirit, he cannot enter the kingdom of God. That which is born of the flesh is flesh, and that which is born of the Spirit is spirit. John 3:5-6

In the previous verses, the Lord explains that without meeting the requirement of the new birth, there is no way of seeing or entering the Kingdom of God.

The baptism in the Holy Spirit is the mark, or seal which guarantees that the person was really born of the Spirit of God and entered the Kingdom of God.

The body of the Kingdom of God is formed of those born of the Holy Spirit, whose head is the Lord Jesus Christ. As a result, only the church that has order, discipline and is sustained by justice, mercy and faith truly belongs to God and the gates of hell will not prevail against it. Matthew 16.18

Therefore, the baptism in the Holy Spirit is not an option. It is a necessity in order to enter the Kingdom of God, and then the Kingdom of Heaven.