Many Christians, mostly Catholics, still today believe that in the practice of communion, the Eucharist, consumption of bread and wine undergoes a physical transformation (Transubstantiation), from bread and wine into the actual flesh and blood of Jesus Christ when it is consumed by the communicant. The Truth of this is found in the Bible, and because it is described in the Bible, it must be True.
Jesus said to them, “I tell you the truth, unless you eat the flesh of the Son of Man and drink his blood, you have no life in you. Whoever eats my flesh and drinks my blood has eternal life, and I will raise him up at the last day. For my flesh is real food and my blood is real drink. Whoever eats my flesh and drinks my blood remains in me, and I in him” (John 6:53)
Now this is a simple binary situation. The bread and wine either actually becomes human flesh and blood through a supernatural physical transformation or it does not. It would not be difficult to find out if transubstantiation actually occurs when consumed by a believing Christian, or not. Modern genetic and chemical analysis of a sample of the contents of a communicants’ ingestion could be done to identify the composition of the remnants of the bread and wine and determine if it is of human origin or is still only bread and wine. And this would be scientific proof, but only in just the instances of the particular actual testing, that the bread and wine did transform, or that it did not. However, if transformation did occur reliably or even frequently, in the absence of deceit, it would greatly shake up our understanding of the truth of reality, but if it did not, it would not eliminate the possibility of supernatural intervention in the mind/soul of the communicant to create the emotional experience of an actual consumption of the flesh and blood of Jesus. Thus the experiment would not eliminate the possibility that it is a religious Truth and not actual truth, thus not subject to scientific analysis as are most religious Truths. The ritual of the Eucharist (Transubstantiation) could also be just symbolic, as many believe it to be, and if so, than it is fully in the realm of religious Truth, and most commonly, religious Truth is imaginary, that is, only real within the human mind. The real damage begins when religious Truth becomes Law, and when one can be imprisoned or put to death for doubting publicly that bread and wine can become the actual flesh and blood of a long dead rabbi.