Where is the kingdom anyway? Heaven or earth?
Matthew 5:8 Blessed are the pure in heart: for they shall see God.
Job 19:26 And though after my skin worms destroy this body, yet in my flesh shall I see God: 27 Whom I shall see for myself, and mine eyes shall behold, and not another; though my reins be consumed within me.
1 John 3:2 Beloved, now are we the sons of God, and it doth not yet appear what we shall be: but we know that, when he shall appear, we shall be like him; for we shall see him as he is.
The promise to the faithful is that they will receive the divine nature and be made equal to the angels.
2 Peter 1:4 Whereby are given unto us exceeding great and precious promises: that by these ye might be partakers of the divine nature, having escaped the corruption that is in the world through lust.
Luke 20:34… The children of this world marry, and are given in marriage: 35 But they which shall be accounted worthy to obtain that world, and the resurrection from the dead, neither marry, nor are given in marriage: 36 Neither can they die any more: for they are equal unto the angels; and are the children of God, being the children of the resurrection.
Angels see God now.
Matthew 18:10 Take heed that ye despise not one of these little ones; for I say unto you, That in heaven their angels do always behold the face of my Father which is in heaven.
The kingdom of heaven will be established upon the earth,
Matthew 6:10 Thy kingdom come. Thy will be done in earth, as it is in heaven.
The purpose of God is to fill the earth with his glory.
Numbers 14:21 But as truly as I live, all the earth shall be filled with the glory of the LORD.
Paul explains what is going to happen:
1 Corinthians 15:20 But now is Christ risen from the dead, and become the firstfruits of them that slept. 21 For since by man came death, by man came also the resurrection of the dead. 22 For as in Adam all die, even so in Christ shall all be made alive. 23 But every man in his own order: Christ the firstfruits; afterward they that are Christ’s at his coming. 24 Then cometh the end, when he shall have delivered up the kingdom to God, even the Father; when he shall have put down all rule and all authority and power. 25 For he must reign, till he hath put all enemies under his feet. 26 The last enemy that shall be destroyed is death. 27 For he hath put all things under his feet. But when he saith all things are put under him, it is manifest that he is excepted, which did put all things under him. 28 And when all things shall be subdued unto him, then shall the Son also himself be subject unto him that put all things under him, that God may be all in all.
When God is all in all, the faithful will both see and know God in a way which we currently cannot imagine.
Revelation 21:3 And I heard a great voice out of heaven saying, Behold, the tabernacle of God is with men, and he will dwell with them, and they shall be his people, and God himself shall be with them, and be their God. 4 And God shall wipe away all tears from their eyes; and there shall be no more death, neither sorrow, nor crying, neither shall there be any more pain: for the former things are passed away.
I hope you find this helpful.