Let us not forget where this idea comes from and explain WHY transubstantiation is a valid system for those who believe in God. The belief comes from the works of Aristotle and how the essence of an object can change in several ways. Transubstantiation is the last step in the
system and perhaps the most important. It looks past the physical and at what the object really is. Hence how the bread and wine are actually in essence the body and
blood of Christ. If it is just a symbol why would Jesus, according to the gospels have not said: "This is like my body sort of I guess if you want it to be so." No he
said: "This is my body and this is my blood." This is what a Catholic priest would say when asked the question. It is really a metaphysical belief and when thought
about is becomes valid. For example if one really believes that a can of Coca-Cola is Pepsi then the essence of it has changed for that individual and they will be
drinking Pepsi in their reality.
*Please note for a non-Christian this will be considered bunk in the highest degree. Yet the theory itself is valid even in non-theological terms.*