16. Again, how natural this unity is in us He has Himself testified on this wise,—He who eateth My flesh and drinketh My blood abideth in Me, and I in him St. John vi. 56.. For no man shall dwell in Him, save him in whom He dwells Himself, for the only flesh which He has taken to Himself is the flesh of those who have taken His. Now He had already taught before the sacrament of this perfect unity, saying, As the living Father sent Me, and I live through the Father, so he that eateth My flesh shall himself also live through Me Ib. 57.. So then He lives through the Father, and as He lives through the Father in like manner we live through His flesh. For all comparison is chosen to shape our understanding, so that we may grasp the subject of which we treat by help of the analogy set before us. This is the cause of our life that we have Christ dwelling within our carnal selves through the flesh, and we shall live through Him in the same manner as He lives through the Father. If, then, we live naturally through Him according to the flesh, that is, have partaken of the nature of His flesh, must He not naturally have the Father within Himself according to the Spirit since He Himself lives through the Father? And He lives through the Father because His birth has not implanted in Him an alien and different nature inasmuch as His very being is from Him yet is not divided from Him by any barrier of an unlikeness of nature, for within Himself He has the Father through the birth in the power of the nature.