As a matter of fact, Christians do have an understanding of God's Kingdom:
Gen 1:1 In the beginning God created the heavens and the earth.
From the beginning of time the Kingdom of God has always existed in two places: in heaven (angles and other spirit beings who were created and subject to their Creator) and on earth (man with whom Jehovah established His government and was present with him in the garden).
There was a kingdom in heaven (Jehovah’s government with angels) and a kingdom on earth (Jehovah’s government with man*). Both kingdoms were corrupted by sin and Jehovah appointed a time when He would judge sin and punish those who rejected His authority. Jehovah’s covenant with Abraham included a promise of an everlasting kingdom on earth through his seed which was a prophecy of the coming of Jesus Christ who was born King of the Jews.
Jesus Was Born King — How Could He Become King In 1914?
Matt 2:2 NWT “Where is the one born king of the Jews? For we saw his star [when we were] in the east, and we have come to do him obeisance.” Matt 27:11 Jesus now stood before the governor; and the governor put the question to him: “Are you the king of the Jews?” Jesus replied: “You yourself say [it]. John 1:49 Na·than′a·el answered him: “Rabbi, you are the Son of God, you are King of Israel.”
Jesus Had All Authority — How Could He Get More Authority In 1914, When He Already Had All Authority?
Matt 28:18 And Jesus approached and spoke to them, saying: “All authority has been given me in heaven and on the earth.
King Jesus would establish the eternal kingdom of righteousness on earth and fulfill His promise to Abraham. In Revelation 21 God will dwell eternally on the newly created earth and be there forever with all those who are His children.
The Jews believed because they were from the seed of Abraham they were automatically heirs (kind of like WT anointed ones automatically go to heaven before 1936) to the kingdom of God on earth. Jesus told Nicodemus (an Old Testament Jew) that he must be born-again (born from above or simply to become a child of God by being spiritually born into God’s family) in order to see or enter God’s kingdom.
WHO WILL ENTER THE EARTHLY KINGDOM?
There are many scriptures that give us the answer to this question, but these few will make it clear to anyone who will believe them. Psalms 37:29; 1 Cor 6:9, and 1 John 2:29 all say that the righteous will possess the earth (earthly kingdom), but the unrighteous will not: Verses taken from the NWT.
Ps 37:29 NWT The righteous themselves will possess the earth, And they will reside forever upon it.
1 Cor 6:9 What! Do YOU not know that unrighteous persons will not inherit God’s kingdom?
Luke 13:43 At that time the righteous ones will shine as brightly as the sun in the kingdom of their Father. Let him that has ears listen.
1 John 2:29 If YOU know that he is righteous, YOU gain the knowledge that everyone who practices righteousness has been born from him.
Note: There is only one way to become a child of God: one must have a spiritual birth. The Bible calls this being born-again. John:3:3 First the physical birth and then a spiritual birth.
So who inherits the Kingdom of God? The righteous will inherit God’s kingdom, but not the unrighteous. In all of scripture there are only two classes of people, the righteous and the unrighteous. These two classes are referred to also as, the righteous and the wicked, or the wheat and the tares, or the children of God vs the children of the Devil, or the saved and the lost, or the saved and the unsaved.
HOW DOES ONE BECOME RIGHTEOUS?
A JW told me recently that by enduring until the end, but that would mean he could earn his righteousness and no one can do that. So how then? Scripture says by faith:
Gen 15:6 NWT And he put faith in Jehovah; and he proceeded to count it to him as righteousness.
Rom 4:4-5 Now to the man that works the pay is counted, not as an undeserved kindness, but as a debt. 5 On the other hand, to the man that does not work but puts faith in him who declares the ungodly one righteous, his faith is counted as righteousness.
Gal 3:26 YOU are all, in fact, sons of God through YOUR faith in Christ Jesus.
Note: One must have a spiritual birth (the physical birth is not enough because your Father is not God) to become a child of God and become part of God’s Kingdom. One cannot believe in a false Jesus and have true salvation—only the true Jesus of the Bible can save a person.
Where does scripture tell one how to become a child of God (that is how to be born-again)?
John 1:11-13 NWT He came to his own home, but his own people did not take him in. 12 However, as many as did receive him, to them he gave authority to become God’s children, because they were exercising faith in his name; 13 and they were born, not from blood or from a fleshly will or from man’s will, but from God.
As anyone can clearly see, one becomes righteous in God’s sight by faith and that faith puts one into God’s family and he/she becomes His child by a spiritual birth. All those who are not born-again are not God’s children and since there are only two classes of people in the world, those who are not born-again will never see or enter into God’s kingdom in heaven or earth. Please take God at His Word and your life will be changed forever.
*JEHOVAH’S KINGDOMS
Isa 37:16 NWT “O Jehovah of armies, the God of Israel, sitting upon the cherubs, you alone are the [true] God of all the kingdoms of the earth. You yourself have made the heavens and the earth.
1Sam 8:7 NWT Then Jehovah said to Samuel: “Listen to the voice of the people as respects all that they say to you; for it is not you whom they have rejected, but it is I whom they have rejected from being king over them.
1!Sam 13:13-14 At this Samuel said to Saul: “You have acted foolishly. You have not kept the commandment of Jehovah your God that he commanded you, because, if you had, Jehovah would have made your kingdom firm over Israel to time indefinite. 14 And now your kingdom [earthly kingdom] will not last. Jehovah will certainly find for himself a man agreeable to his heart; and Jehovah will commission him as a leader over his people, because you did not keep what Jehovah commanded you.”
Acts 1:6 When, now, they had assembled, they went asking him: “Lord, are you restoring the kingdom [the earthly kingdom] to Israel at this time?”
Prov 21:1 A king’s heart is as streams of water in the hand of Jehovah. Everywhere that he delights to, he turns it
Rom 13:1-5 Let every soul be in subjection to the superior authorities, for there is no authority except by God; the existing authorities stand placed in their relative positions by God. 2 Therefore he who opposes the authority has taken a stand against the arrangement of God; those who have taken a stand against it will receive judgment to themselves. 3 For those ruling are an object of fear, not to the good deed, but to the bad. Do you, then, want to have no fear of the authority? Keep doing good, and you will have praise from it; 4 for it is God’s minister to you for your good. But if you are doing what is bad, be in fear: for it is not without purpose that it bears the sword; for it is God’s minister, an avenger to express wrath upon the one practicing what is bad.
WHO BELIEVES THE DEVIL’S LIE?
Matt 4:8-9 Again the Devil took him [Jesus] along to an unusually high mountain, and showed him all the kingdoms of the world and their glory, 9 and he said to him: “All these things I will give you if you fall down and do an act of worship to me.”
John 8:44 YOU are from YOUR father the Devil, and YOU wish to do the desires of YOUR father. That one was a manslayer when he began, and he did not stand fast in the truth, because truth is not in him. When he speaks the lie, he speaks according to his own disposition, because he is a liar and the father of [the lie]
Note: Satan lied to Jesus about giving him the kingdoms of the world—they were not his to give. The kingdoms of the world belong to Jehovah and He is in control of the governments on earth, not the Devil. When Scripture calls Satan “the god of this world,” it simply means that he is the master deceiver and liar from the beginning as he was with Eve.
http://www.bwce.org/kingdom_of_heaven.html