In 1492 Christopher Columbus 'discovered' America and named the inhabitants 'Indians' thinking that he had reached India. But just what was there to 'discover'? The Americas and the Indians had been there well before Columbus. Dark Ages belief, including such fostered by the Catholic Christian Church, was that the earth was flat and if one sailed far enough from land they would just fall right off the edge. Science scoffs at such an absurd understanding, mocking those who held it in ridicule. But science has just as large of a blunder in their own closet. For years science has concluded upon the big bang theory and that since the universe began with a central 'big bang' the universe would have a limited dimension, a limited size beyond which there would be nothing. Recently science has reversed themselves upon that concept of a limited universe as the further away they are able to reach in their observations they are finding that the 'universe' just goes on and on and on, even more so than the Energizer Bunny. And science now has concluded that there is no end to the 'universe' and even if so, then there are other such universes endlessly continuing on forever. And with their great prowess, science in their pride, at least a 'select' elite group, have so determined that there is no God. Just what is it about an infinite God and of eternity has science heretofore not understood? God's or Gods' heavens are infinite and eternal and always have been, and science is just now 'discovering that!
What is Heaven? Perhaps we will better understand that when we get there but for sure the heavens are infinite and eternal and always have been and always will be. King David in Psalm 110 spoke concerning the 'LORD' of his 'Lord'. And when Jesus so quoted David in his representation of himself as the Son of God (Mark 12:36 & Luke 20:42), the Jews did mock him and eventually killed him on that charge, that he claimed to be the Son of God (Mark14:61-64; Matthew 26:63-66; Luke 22:67-71). Of course Jesus was and is the same being as the spirit God Jehovah of the Old Testament. But just as sure as Jesus taught his disciples to pray beginning with 'Our Father Who Art In Heaven', so do we, like Jesus, have a Heavenly Father in Heaven. The Father of our spirits. And Jesus, the God of the Old Testament, when he prayed in the Garden of Gethsemane, called upon his Father and our Father saying, 'Abba' or 'Papa', for indeed there is a Celestial God, Jesus' and our 'Papa', the 'LORD' of our 'Lord' Jehovah, even Jesus Christ is He who is also the Father of our spirits.
It is deep doctrine to speak of Gods upon Gods throughout the infinite and eternal heavens, and perhaps that is also best left to when we pass beyond this veiled earth life into that eternity to so really further comprehend that as well. Yet the Book of Abraham in the Pearl of Great Price has revealed that there is a place where our God's Heaven is and it gives it a name, 'Kolob'. More precisely, Kolob is a 'governing star' and some speculate that it is one such governing star at the center of our Milky Way Galaxy. I don't know that, but such is a theorem to so postulate and perhaps provide some understanding. We know that our Celestial Heavenly Father has a Celestial glorified body of flesh and bone, and now after his resurrection, so does Jehovah/Jesus Christ (D&C 130:22). And our temporal ministering God Jehovah, even Jesus Christ, who was anointed as such by the Celestial Father, now stands and sits at the right hand of God our Heavenly Father as the scriptures do teach, and His throne in His Heaven. Now without speculating further upon this, which is also likely best left to when more is revealed or even upon our leaving this mortality, I'll proceed to the next question.
Now you might note that I skipped a question. I'll get back to it. The best answer to just what we are going to be doing in God's Heaven is likely best answered by a statement of God's/Gods' purpose, work and glory as given by Moses in the Book of Moses in the Pearl of Great Price. For God told Moses just what his central purpose, that is what his work and his glory was. God told Moses, "For behold, this is my work and my glory——to bring to pass the immortality and eternal life of man." (Moses 1:39) And then God told Moses concerning this earth in the manner like unto that which is recorded in the Jewish first book of the Torah Old Testament, that is Genesis. And God also had told Moses saying: "The heavens, they are many, and they cannot be numbered unto man; but they are numbered unto me, for they are mine. And as one earth shall pass away, and the heavens thereof even so shall another come, and there is no end to my works, neither to my words."
We are told that as God is, man may become, for when we see him, we shall be like him, for we shall see him as he is. And if God's work is an endless course with an endless intent and purpose, that of bring to pass the immortality and eternal life of man; so also we ought to consider that there will be plenty of work enough to do to keep us busy beyond the mere playing of harps and singings hymns for all eternity.
I now return to the question I skipped and also to arrive at that of the title of 'God's Greatest Reward'. What is heaven like? Well based upon the premise that God's work and glory is to bring to pass the immortality and eternal life of man, I would conclude that Heaven is like 'Family'. 'I Am a Child of God'. You are a child of God. We are the children of God. He is our Heavenly Father. And not to 'make reason stare', 'we've a Mother there' as well. Heaven is Father, Mother, Sister, Brother; Grandfather, Grandmother, Grandson, Granddaughter. The powers of heaven and the powers of procreation are sacred and definite, eternal and infinite. The order of heaven is a Patriarchal Order.
All will live again and be resurrected, but not all will retain these procreative powers of God. That is a part of our testing here upon this earth. Is it any wonder why we hold out to the world the sanctity of marriage as being between a man and a woman for the intent and purpose of family and to God's end purpose, work and glory to bring to pass man, his immortality and eternal life? God's design for women is to be mothers and God's design for men is to be fathers. In this man is a participate with God in God's great plan, work and glory. A husband and wife may be sealed as such that in eternity they may continue in God's work. Those who are so rewarded will have obtained their reward in accord with what they have done here in this life. And it is these who adhere to and support this heavenly family unit, as well as the commandments of God, who will be brought home to dwell in God's heaven and in God's presence. Those who do not live according to these principles and concepts of 'family', well NOT receive God's Greatest Reward.