What is a Christian?

I was brought up in a Christian home. 

That doesn't make you a Christian. 

My mother always went to Church. 

That doesn't make you a Christian. 

I believe in doing good, helping others. 

Quite right, too, but so do most people. That doesn't make you a Christian. 

I believe in God. 

Most people say this, but that doesn't make you a Christian. Many people think they are Christians but rarely bother about Jesus Christ. 

Well, what is a Christian, then? 

Let's begin at the very beginning....