… He died for all, that those who live should live no longer for themselves, but for Him who died for them and rose again. Therefore, from now on, we regard no one according to the flesh. Even though we have known Christ according to the flesh, yet now we know Him thus no longer. Therefore, if anyone is in Christ, he is a new creation; old things have passed away; behold, all things have become new. (2 Corinthians 5:15-17)
Theodoret of Cyrus, writing in the 5th Century, notes that the new creation will not be fully realized until after the general resurrection of all happens in the eschaton. It is only then that we and creation will be freed from corruption. In this life, even the deified still suffer corruption and die. The incorrupt and immortal life will be ours only when God’s Kingdom is fully established. Until then, even though God’s Kingdom is breaking into this world, we still do not experience the fullness of the new creation. Once the new creation happens, life will be nothing like we know it today. That is a joyful experience which we must await. Theodoret says:
He [St Paul] said this also in writing to the Corinthians: ‘So that if anyone is in Christ, there is a new creation’ (2 Corinthians 5:17). Now, by new creation he refers properly to the transformation in things coming after the resurrection from the dead: at that time the creation will be freed from the corruption affecting it, and human nature will be clothed with immortality. He shows saving baptism to be a kind of image of the future realities: in it we lay off the old person and are clothed with the new, and by setting aside the burden of sins we receive the grace of the Spirit. (COMMENTARY ON THE LETTERS OF ST PAUL Vol 2, p 24)
In Baptism we put on Christ, yet in this world and in this life, Baptism remains but an image of the future reality of the new creation. St Paul wrote: “Not all of us shall sleep, but we shall all be changed” (1 Corinthians 15:51). God’s Kingdom will come before all humans have died. All of us will not experience death (sleep), but all of us will experience the transfiguration of becoming the new creation in which corruption, suffering and death have all fled away. Life in the Kingdom will not be just an endless version of life in this world, but a new creation which we cannot even imagine.
… because the creation itself will be set free from its bondage to decay and obtain the glorious liberty of the children of God. We know that the whole creation has been groaning in travail together until now; and not only the creation, but we ourselves, who have the first fruits of the Spirit, groan inwardly as we wait for adoption as sons, the redemption of our bodies. (Romans 8:21-23)
Beloved, we are God’s children now; it does not yet appear what we shall be, but we know that when he appears we shall be like him, for we shall see him as he is. (1 John 3:2)
Fraternized 
So the new birth and the new creation are not the same. As baptism by water and spirit is the sacrament of initiation, I have understood that it effects an ontological transformation. Perhaps that’s what you mean, but as you have written it here, it sounds to me as though baptism is simply a shadow of the new creation that is to come. Could you clarify this for me, Father Ted?
Not sure if I can clarify it. I think Theodoret and many Church Fathers were clear that heaven is not simply going to be this life made perfect lasting for ever and ever, but rather is going to be something so different (a new creation) that we can’t even imagine it yet. We may have brief glimpses and experiences of it in this world, but they will always only be a foretaste of what is coming. No matter how wonderful these experiences are, they still cannot measure up to what is coming. Keep in mind that we still rely on our physical senses to experience the spiritual world and we interpret these experiences through our understanding of the senses (touch, taste, smell, feeling, hearing, sight). In that new creation we will be seeing with the eyes of our heart, experiencing salvation in ways we cannot know imagine. The pure in heart will “see God” – obviously it is not the eyes with which we will be seeing God but our hearts. We won’t know what that means until we get there. Two quotes to consider:
If any one imagines that he knows something, he does not yet know as he ought to know. (1 Corinthians 8:2)
Beloved, we are God’s children now; it does not yet appear what we shall be, but we know that when he appears we shall be like him, for we shall see him as he is. (1 John 3:2)