At the core of this topic is the consideration of creation, both the “old” (original) and the new.
God immediately created Adam. This is direct creation relative to the Word who created the cosmos and its sole initial inhabitant who was in the image of God (Imago Dei). God also immediately created Eve, though not from the dust of the ground but from the rib of Adam.
Immediate creation is precisely this. The direct creation of God in a specific state of being.
Mediate creation is procreation. The indirect (intended) creation of God, originally to be the means of reproducing the same specific state of being in offspring as life from life (both physical and spiritual life; bios and zoe).
But prior to any procreation by Adam and Eve, they lapsed into spiritual death and sin. (There is a lengthly explication of the ontological and economic facets of that event, but that is for another epic-length post.) The result is that ALL procreation was subsequent to the onset of spiritual death and sin in man, and the cosmological implications are usually lost on those who have an anthropological focus.
The image of Seth after Adam is the state of being for ALL mankind after the Edenic lapse of man, and thus the cosmos itself. All humanity has been procreated as life from life, but without spiritual life while being physically alive. The delusion is that physical life means that the underlying reality of existence for each human makes them an authentic hypostasis (“person”), but this is NOT the case.
With sin in the nature of all mankind because of spiritual death (cessation of constant communion with God) and also in the members (the fleshly propensity unto action according to state of being), mankind is NOT the creation of God according to divine order.
This requires a new creation. A new heavens and a new earth. And for man to be a new creature. Without resurrection unto spiritual life in this physical life, man is not the creation of God as ordained by divine order. So once death took Adam and Eve, the remainder of ALL of humanity is NOT the immediate creation of God. It’s the mediate and indirect procreation of man himself with corruption innate to man’s state of being.
The altered state of being of post-Edenic man is in a condition that corresponds neither to the original creation NOR the new creation. The new creation is only that which is DIRECTLY AND IMMEDIATELY created anew by God; and this is accomplished by the Son as Theanthropos by His Incarnation, life, death, burial, resurrection, appearing, ascension, and seating in heavenly places.
The application of IMMEDIATE creation for mankind is by a specific functionality that God has ordained for this purpose. To insist that all men are universally saved is to not understand that all men since Eden have not existed in a state of being that can be considered the creation of God. It’s an altered condition and state of being.
There’s literally a 300-page thesis to delineate all of this, so this venue won’t allow complete explanation. But the ultimate bottom line is that no individual authentically exists until the Son, by hypostatic union, immediately creates each individual anew as a new creature.
The compound issues here are all the same considerations that are ontological regarding states of being. No man born by mediate procreation has authentic life; only being physically alive while being spiritually dead. So everyone is quite literally a spiritual zombie until they are resurrected in this life. They have no status for their underlying reality of existence. They are not part of creation in this sense.
So when scripture refers to creation, it is NOT including those who have no valid underlying reality of existence. They share the same plight as the cosmos, which has been redeemed in Christ. So the ONLY way for man to have status as created is to be hypostatically joined to Christ by faith and grace. It can be God’s work alone, for man has no foundation of “being” from which to “do” such things. Man cannot create, immediately OR mediately. Even procreation is according to divine order but corrupted; for it is the means of the propagation of human souls who are spiritually dead (with no ability for constant communion with God that is the source of life).
There is much more to this, but this is the basic introduction to the fact that post-Edenic man is not part of creation because of corrupted mediate creation as procreation. Man’s state of being is incompatible with both God and the ultimate new creation of the cosmos. And God, in Christ, is reconciling His creation to Himself. Those who are not redeemed in this life are those who remain in their state of being that is not part of creation. The lake of fire is all they have when the only cosmological consitution they are compatible with is destroyed and gives rise to the new creation.
These lost souls have no place to which they can return, and no place to which they can go. They are in the very void that is their evil and sin. This is their torment, and God didn’t do it to them. They are casualties of the enemy of men’s souls who attempted to set his throne above the most high. They are “lost” because they have no ontology to which they are compatible. And God’s mercy STILL rejoices against judgment on their behalf.
The odd thing is that so many blame God for the lake of fire, but few ever blame the serpent for it being the altered state of existence for so many in both this life and the life to come. Sad.