How does a Catholic refute this assertion? I’m sure I could come up with a definitive response perusing through my apologetics links as well as this site, but what would be yours?
John 6:53 - Unless you eat My flesh
Unless You Eat the Flesh of the Son of Man and Drink His Blood You Have No Life In You
Are these words of Jesus from John 6:53 to be taken literally or figuratively? The Roman Catholic Church teaches the context of John chapter six and the above headlined verse 53 are literal. Thus Jesus is giving absolute and unconditional requirements for eternal life. In fact, this literal interpretation forms the foundation for Rome’s doctrine of transubstantiation – the miraculous changing of bread and wine into the living Christ, His body and blood, soul and divinity. Each Catholic priest is said to have the power to call Jesus down from the right hand of the Father when he elevates the wafer and whispers the words “Hoc corpus meus est.” Catholics believe as they consume the lifeless wafer they are actually eating and drinking the living body and blood of Jesus Christ. This is a vital and important step in their salvation and a doctrine they must believe and accept to become a Catholic.
If priests indeed have the exclusive power to change finite bread and wine into the body and blood of the infinite Christ, and if indeed consuming His body and blood is necessary for salvation, then the whole world must become Catholic to escape the wrath of God. On the other hand, if Jesus was speaking in figurative language then this teaching becomes the most blasphemous and deceptive hoax any religion could impose on its people. There is no middle ground. Therefore the question of utmost importance is – Was the message Jesus conveyed to the Jewish multitude to be understood as literal or figurative? Rome has never presented a good argument for defending its literal interpretation. Yet there are at least seven convincing reasons why this passage must be taken figuratively.
Here are his reasons pro-gospel.org/01/ea-019.php