I’ll be the first to admit that at times I have been wrong about being a Christian.
I’ve mistaken being conformed outwardly for being transformed inwardly. I sometimes have an unconscious tendency to adapt to my environment. I spend time with Christian friends and before long I look, act, and sound just like them. These changes may be good but they are usually temporary and should not be mistaken for true holiness. They are merely superficial responses to spiritual peer pressure.
But sanctification (God’s work to make me holy) is not temporary adaptation to my environment. It is not me looking more like other Christians, it is me looking more like Jesus. I’m being remade after the image of the One who created me (Colossians 3:10). The ongoing redemptive process doesn’t make me look more “churchy” it makes me look like Christ.
Anything less just isn’t Christian.