You aren't a Christian just because you say you are. You aren't a Christian just because you attend a church. You aren't a Christian just because you tithe. You are a Christian because you are willing to live and die for the name of Jesus Christ, you are willing to live and die for his will to be done, you are willing to live and die for His glory. The worst thing you could ever do is pretend to be a Christian. That is a judgment you don't want to face.