“His own Word, our Lord Jesus Christ and of all these His earthly creatures He reserved especial mercy for the race of men. Upon them, therefore, upon men who, as animals, were essentially impermanent, He bestowed a grace which other creatures lacked–namely the impress of His own Image, a share in the reasonable being of the very Word Himself, so that, reflecting Him and themselves becoming reasonable and expressing the Mind of God even as He does, though in limited degree they might continue for ever in the blessed and only true life of the saints in paradise. But since the will of man could turn either way, God secured this grace that He had given by making it conditional from the first upon two things–namely, a law and a place. He set them in His own paradise, and laid upon them a single prohibition. If they guarded the grace and retained the loveliness of their original innocence, then the life of paradise should be theirs, without sorrow, pain or care, and after it the assurance of immortality in heaven. But if they went astray and became vile, throwing away their birthright of beauty, then they would come under the natural law of death and live no longer in paradise, but, dying outside of it, continue in death and in corruption. This is what Holy Scripture tells us, proclaiming the command of God, ‘Of every tree that is the garden thou shalt surely eat, but of the tree of the knowledge of good and evil ye shall not eat, but in the day that ye do eat, ye shall surely die.’ ‘Ye shall surely die’–not just die only, but remain in the state of death and of corruption.”
Athanasius. On The Incarnation of the Word. 44-53. Kindle Edition.