It seems to me that William Arkle explained this (in terms I can grasp and validate intuitively) better than almost anyone else I have encountered.
Arkle generally used the word 'friends' (specifically defined) to try and capture what God wanted us to become (in the fullness of eternity) - meaning by this that God wanted to raise us to full divinity, to bring us to a spiritual maturity, such that we could become like ideal friends.
This raising and maturing of God's children is the purpose of creation - to provide the necessary experiences.
Friends is nowadays, however, a rather weak word - since most modern people have few (or no) friends in Arkle's sense - just colleagues, acquaintances, buddies... Friendships, as we know them, are far feebler than marriages and families (even the trivialised and besieged modern marriages and families)... how many friends would move house to be near a friend, or give-up work to look after an ill friend? It happens, but far less often than with spouses, parents or children.
In that sense family relationships are closer to what God wants from us - and Arkle used the analogy of a father's possible relationship with (for example) a grown-up son who has himself married and has a family; in an ideal situation when both become friends as well as remaining father and son. If this ideal is extended horizontally, to include non spouses and not family - we have a vision of the heavenly society.
As a picture of this ideal and its extension, the Fourth Gospel explicitly shows us Jesus and his disciples; and the siblings Lazarus, Martha and Mary; and Jesus teaches us the way that this love works.
We can also see how this Love grows and extends incrementally, person by person, through time - and not by some sudden generalised and imposed state of being. So we need tot suppose that Christians are supposed - suddenly and somehow - to love everybody in this world indifferently; and the same would no doubt apply in the eternity to come.
As both friends and as family we therefore have a vision of God's ideal, and we can see how and why Love is the central quality necessary; and we can see the reason for the emphasis on love in the Fourth Gospel. But this love is - in an important sense - incomplete; because it describes a static state; whereas we know that love is dynamic, fluxing, changing - we love people as we do things together...
So what is it that God wants that we do, ideally, in Heaven? The answer is simple enough - it is to participate in Creation; to become colleagues in the work of Creation.
But for this to be clear and comprehensible, we need to remember that God's Creation is composed of Beings, and only Beings. God did not create by some kind of celestial physics of life-less minerals; on the contrary, everything God created is and always has been alive, conscious and purposive. It is this living, developing Creation in which we are to participate. And this includes the creation, begetting, of persons - in a general sense the having of 'children'.
What God wants from us is two fold. We are God's children, and God wants us on the one hand to grow to become fully divine friends, bound by love; and on the other hand God wants us to participate in the divine work of Creation.
The two things go together, and indeed grow together.