I was told by my Russian Orthodox friends on several occasions that according to their beliefs only members of the Orthodox Church are Christians. (For example, they pointed out that my statement that most people in the United States were Christians was incorrect because most people in the United States were Protestants and not Christians.) They claimed that according to the Russian Orthodox Doctrine:

> 
> * A Christian is a member of the One Holy Catholic and Apostolic Church (Nicene Creed).
> * The Orthodox Church is the One Holy Catholic and Apostolic Church.
> 
> 
> Consequently, a member of the Russian Orthodox Church cannot say that a
>  Catholic or a Protestant is a Christian (it would be a sin to do so; as it would be a sin to say that a pagan deity is God).
> 
> 
> 

**Is it true that members of non-Orthodox churches are not Christians according to the Russian Orthodox Doctrine? Is it a sin to call them Christians according to Russian Orthodox doctrine?**