Com-munion is literally ‘in union.’
Anglicans are not ‘in union’ with Rome, are they?
Would you, englishredrose, be willing to state to everybody in the Catholic Church (and everybody in your Anglican Church, and the entire world on satellite TV etc.)as you took the Eucharist there, “I believe in everything your Church teaches and that is why I take communion with you.”
If you do not believe in everything the Catholic Church teaches and would not say so, why would you want to take the Eucharist when by doing so you are implying that yes in fact you DO believe everything the Church teaches and are thus taking this as a sign of your unity of belief?
It works for us too. Catholics would not go into an Anglican Church and say as they received the Eucharist there, “I believe in everything YOUR Church teaches and that is why I take this as a sign of union with you.” We do not believe in all your Church teaches.
God told us to be One, but He didn’t say, “Oh, and by the way, you can accept the beliefs of other Christians even if you don’t believe them and they contradict what you are taught as revealed truth, just so it LOOKS like you are all in agreement even when you’re not.”