It seems harsh to say that someone who faithfully attends church, is there every time the door is open, might not actually know Jesus. The difficulty with this view is that Jesus Himself spoke most harshly about those who attended synagogue the most. He criticized them because they were all about the outward appearance while not having an actual relationship with God. Pastor Mark is warning us against slipping into the same mindset. We need to remember that we go to church to deepen our relationship with God and with likeminded people, not to impress folks by our false piety.