Most people I know are for sure Christian.
How do I know it?
I don’t follow them to church. It’s not by their behavior.
It’s by them advertising that they are Christian.
Most people I know do not for sure know I’m an atheist. It’s because I don’t feel the need to advertise. The ones who do know found out because I responded to a question about my beliefs.
I don’t have a problem with you advertising. After all, your religion commands you to do it. Just don’t complain when others advertise, too. It’s like Wal-Mart taking it personally when Target runs an ad.
They’re not Christians simply because they say so. If their behavior doesn’t match what Jesus taught, they’re not Christian.
Talk is cheap and easy.