EWTN.com - receiving communion: "receiving communion
Can a Catholic receive Communion at a Lutheran Church? If not, what is the explanation?
Answer by Fr. Jay Toborowsky on 10/17/2008:
No. Lutherans do not have the same beliefs and understanding as Catholics do with regards to the Eucharist. In addition, we believe that only a validly ordained Priest may say Mass and confect the Eucharist. For a Catholic to receive the Lutheran 'communion' would be to say that there's a unity between the Church and the Lutherans that does not yet exist."