Everything you do as a Christian impacts the body. It either helps or hurts other Christians. There is no private Christianity. No strictly personal faith. Each of your sins and all of your faith impacts me. And the rest of the church.
All of us struggle with conceit. We all tend to think more highly of ourselves than we ought to. Most of us, including myself, have a way bigger superiority problem than an inferiority problem. In fact, conceit was a problem in almost every church that Paul wrote to. If you don’t think you are conceited, then you are probably conceited.