The preacher then went on to fill the airwaves with the same stuff I used to hear growing up in fundamentalism, that our identity as a Christian is tied up in how we dress, the music we listen to, the friends we have, the church we go to, and the version of Scripture we use. This type of teaching is nothing but a big, stinking pile of bovine excrement. Worse than that, it is the same thing that the Judaizers were saying during the first century. They were telling folks that their identity in Christ included circumcision, and keeping the ceremonial laws. I really don't see a whole lot of difference between that and what this guy was preaching.
It is true that the thief comes to steal our identity in Christ. One of the things he uses is preaching like this that tells a Christian that their identity is in a certain list of behaviors. Look through Scripture and you will find a lot of passages that deal with who we are in Christ. You will not find one that refers to dress, or behavior (unless you take an Old Testament passage out of context). Our identity in Christ is not in anything we do or don't do. It is in Christ. Period. We are who we are because of Whose we are. We children of the living God, and our Father loves us and is pleased with us.
Our identity does not rise out of what we do. It rises out of who God is and what Christ has done.