Id say it could mean that they were a church which had not "clothed" itself with the good works which ought to tell the world that they are following Christ.
The church as a whole very well could have been teaching the wrong things. They had become lacksadaisical, lazy, and uncaring. They no longer had a consistently good witness for Christ, and needed to come back to the realization of what Christ had done for them and what He had to offer them.
The church as a whole very well could have been teaching the wrong things. They had become lacksadaisical, lazy, and uncaring. They no longer had a consistently good witness for Christ, and needed to come back to the realization of what Christ had done for them and what He had to offer them.