To begin with,
It is God Himself. He is the King of the Kingdom.

You come into  His Kingdom by given your life to Jesus and confessing Him as your Lord and Saviour and believing Him in your heart.

Romans  10:9 That IF THOU SHALT CONFESS WITH THY MOUTH the Lord Jesus, and shalt BELIEVE IN THINE HEART that God hath raised him from the dead, thou shalt be saved. 

10:10 For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation.

This is what brings you to the Kingdom of God.

You come into the Kingdom of God through Jesus Christ because He is the way to the Father.

John  14:6  Jesus saith unto him, I am the way, the truth, and the life: no man cometh unto the Father, but by me.

Jesus brings us into the Kingdom, to the Father by given our lives to Him. Which we have stated above how to give our life to Him by confession with our mouth and believing in our hearts.

Yes that’s all to how to come into the Kingdom.

Jesus said this.
John  3:16 For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life. 

3:17 For God sent not his Son into the world to condemn the world; but that the world through him might be saved.

The first benefit is you will not perish in hell that’s eternal damnation and the second one is that you’ll have everlasting life. That means you will have eternal life and also reign with Him forever.

Eternal life is the life of God as God as it! You have it as you give your life to Jesus as shown in John 3:16 and this is also because it was promised to us.

Titus  1:2 In hope of eternal life, which God, that cannot lie, promised before the world began;

Eternal life is revealed also as God.

John  17:1 These words spake Jesus, and lifted up his eyes to heaven, and said, Father, the hour is come; glorify thy Son, that thy Son also may glorify thee: 

17:2 As thou hast given him power over all flesh, that he should give eternal life to as many as thou hast given him. 

17:3 And this is life eternal, that they might know thee the only true God, and Jesus Christ, whom thou hast sent.

When you give your life to God, you have eternal life and you become a son of God. This is what it means when you hear also that you have life as God has it. When you give your life to Jesus, the Spirit of God or the Spirit of Jesus comes into you and then witnessing to you that you’re now a child of God. That’s life.

Romans  8:16 The Spirit itself beareth witness with our spirit, that we are the children of God:

Even as you become a child of God, that Spirit of God on your inside will begin to guide you to the things of God that will enhance your growth, what you’ll learn to do is to obey that Spirit of God, knowing well that He can not lead you to error. Submitting ourselves to Him more in obedience brings us into deeper things in Him more. Obedience opens the more door into the revelation of Christ for an entrance for us into Him.

Romans  8:14 For as many as are led by the Spirit of God, they are the sons of God. 

8:16 The Spirit itself beareth witness with our spirit, that we are the children of God: 

8:17 And if children, then heirs; heirs of God, and joint-heirs with Christ; if so be that we suffer with him, that we may be also glorified together.

This is to tell you again that we are children of God.

Galatians  3:26  For ye are all the children of God by faith in Christ Jesus.

What God is bringing us into as His body, who are His children is this, through the ministry gift, is be come to His fullness.

Ephesians  4:11 And he gave some, apostles; and some, prophets; and some, evangelists; and some, pastors and teachers; 

4:12 For the perfecting of the saints, for the work of the ministry, for the edifying of the body of Christ:

4:13 Till we all come in the unity of the faith, and of the knowledge of the Son of God, unto a perfect man, unto the measure of the stature of the fulness of Christ: 

4:14 That we henceforth be no more children, tossed to and fro, and carried about with every wind of doctrine, by the sleight of men, and cunning craftiness, whereby they lie in wait to deceive;

Galatians  4:19 My little children, of whom I travail in birth again until Christ be formed in you,

We must remember that there was a time that we are once in sin but now have been  redeemed. This must be what we see that push us to get souls for the Lord and not leave them to their sins.

Titus 3:3 For we ourselves also were sometimes foolish, disobedient, deceived, serving divers lusts and pleasures, living in malice and envy, hateful, and hating one another. 

3:4 But after that the kindness and love of God our Saviour toward man appeared, 

3:5 Not by works of righteousness which we have done, but according to his mercy he saved us, by the washing of regeneration, and renewing of the Holy Ghost; 

3:6 Which he shed on us abundantly through Jesus Christ our Saviour; 

3:7 That being justified by his grace, we should be made heirs according to the hope of eternal life.

In addition, Christ is a Son. He is an heir of God. We became Sons of God as we come to the Son of God, Jesus. What Jesus do to people that comes to Him is to make them what He is. Remember the prayers He prayed to the Father. It was a prayer to bring us into Them. So that we can actually be the fourth person in one with Them.

John  17:1 These words spake Jesus, and lifted up his eyes to heaven, and said, Father, the hour is come; glorify thy Son, that thy Son also may glorify thee: 

17:19 And for their sakes I sanctify myself, that they also might be sanctified through the truth. 

17:20 Neither pray I for these alone, but for them also which shall believe on me through their word; 

17:21 That they all may be one; as thou, Father, art in me, and I in thee, that they also may be one in us: that the world may believe that thou hast sent me.

Jesus is an Heir of God and because we submit to that Sonship that He also is, we join Him to become an heir of God, joint heir. This does not mean lower in heir. But equal in heir. Even an heir can miss what he has if he doesn’t know they were actually his.

So I conclude with this.

Galatians  4:1 Now I say, That the heir, as long as he is a child, differeth nothing from a servant, though he be lord of all; 

4:2 But is under tutors and governors until the time appointed of the father. 

4:3 Even so we, when we were children, were in bondage under the elements of the world: 

4:4 But when the fulness of the time was come, God sent forth his Son, made of a woman, made under the law, 

4:5 To redeem them that were under the law, that we might receive the adoption of sons. 

4:6 And because ye are sons, God hath sent forth the Spirit of his Son into your hearts, crying, Abba, Father. 

4:7 Wherefore thou art no more a servant, but a son; and if a son, then an heir of God through Christ.

Now becoming a Son guarantee you becoming an heir. A son according to the revelation of Jesus is an heir of God, and aligning to that Sonship makes you an heir.
Keep walking…