I think you are referring to Roman Catholic dogma, the doctrine of transubstantiation.
As for human sacrifice, the only attribution I know of is Abraham being asked to offer his son, which was apparently a test of his loyalty, and it was ultimately not asked. Like much of the Hebrew accounts of Yawhweh, he sounded more like an earthly emperor than a divine being, in nature and temperment.
As such, there are numerous passages where people were struck down for disobedience, which continued right into the New Testament and Christianity when Ananias and Sapphira lied about their charitable contributions. And, the New Testament concludes with the Apocalypse, a final purge of humanity.
Hebrew accounts are almost too many to remember. Children of Israel in the Wilderness of Zin after the Golden Calf. the Egyptian Army in the Reed Sea, the entire human race in the Great Flood, the prophets of Baal at Kidron Brook, and on and on.
Judeo-Christian deity either changed as he dealt with mankind (a heresy), or man's perception of the deity changed as humanity evolved. Unsurprisingly, people look at the same things and find different meaning, impacts, and conclusions. We are all products of our cultures, including indoctrination by religions and by secular institutions.
Ironically, Christianity's god is remarkable because of the attribution of mercy and forgiveness, which stands in contrast to most of the world religions.
Whether a member of a religion or against all religion, studying mankind's religions is an insightful aspect of sociology.