"Then any professed Christian is automatically an autoracist."
No.
If a man identifies himself as a Christian to indicate what his beliefs are, that is not autoracism.
If a man joins a church, or any other organization, because he believes he benefits from it, that is not autoracism.
If a man does either of these, and finds either his identity or self worth in those things, rather then in what he really is, that is autoracism. Obviously a sincere Christian is one because he thinks he's better for being one than not, because it is his belief. That is not autoracism. If he thinks he gains some kind of privilege or social status from that, it would be autoracism. The same applies to belonging to a church.
Hank
Still not quite sure I see the difference between believing you're better because you're a christian and or believing that by being a christian, you're better.