Non-Christian joining a Christian Church?

What is the definition of a Christian? The definition of Christian is, “professing belief in Jesus as Christ or following the religion based on the life and teachings of Jesus.” In the question and answer assignment we were suppose to discuss Pojmans’ analysis of Jesus Christs’ ethics and if a “Christian Atheist” in this case Robert Jenson would agree with this analysis. I do not think that Robert Jenson would agree with this analysis or even get any part of the picture trying to be painted here because he does not believe in god. During the week in class we discussed how Robert Jenson could be allowed to enter a Christian church when he does not believe in Jesus Christ. He said that the reason why he wanted to join the church is because it looks good and he wanted to be able to talk about political views and church is a good place to communicate with people about these issues. In my view, this is a terrible reason to join a Christina church and a Christian church should not allow someone to join if they do not believe in Jesus Christ. The definition of a Christian is someone who believes in Jesus Christ so someone who does not fit the definition of a Christian should not be able to join a Christian church. I’m interested to find out what others feel about this subject?