I am a Christian. I think that statement means something different to everyone. To me it means to be living by the Bible. The whole Bible. Truth, love, obedience and all that. There are so many people around that SAY they are a Christian, but I am not convinced they have really looked into what it means to BE one.
I can say I am a Kiwi. I am a Kiwi. It means I am from New Zealand (affectionately), I grew up there, I was raised there. I know New Zealand. I love New Zealand. I understand the culture and laws, what is acceptable and what is not (in most general situations) etc... So I know what it means to BE a Kiwi. However, I could just as easily say 'I am Viking'. I have never been to Scandanavia. I don't really understand why they invaded anywhere (if, in fact, they DID invade anywhere), I don't know what language they speak or understand their culture. But I used to read my brother's Astrix comics when I was younger and I always thought it would be pretty cool to do the stuff he did. And the clothing they wear is pretty cool too. I like the big cave-like structures they hang out in, and the men look so big and strong! So if I say I am a viking, then I would be labled as being as cool as them.
And then my claim to Vikingdom is shattered when a REAL Viking comes along and proves to everyone who believed me (or those that are happy to just go along because I wasn't trying to turn them into a Viking), that I am SO not a Viking. But this real viking that has come along, doesn't even need to say anything about what he is, because people can just tell. He is wearing the gear, speaks Norwegian (or whatever that exotic tongue is speaking!), acts, looks and sounds like a Viking. Has an amazing knowledge of the history of the viking, and his eyes sparkle a little when he talks of his Motherland... He is a Viking. I am not. Shot down.
So how can you tell I am a Christian? Ask me. Do my eyes sparkle a little when I talk of my God? How about when I talk of what He did for me? How about when I talk of what He has done for you? My heart is different. I don't want to do the things He doesn't want me to do. I am free. I live free. If I do things, think things, say things that are not "Christian", I would want to make them right. Apologise when necessary. Bridge gaps. Have healthy, honest relationships. I live my life striving DO what the Bible says is good for me. And most of the time it's hard. It would be so easy to live by my own choices. But I would be a slave to this world, only to go to Hell for eternity once this struggle is done.
If someone (including me) says they are a Christian, I challenge you to ask them what that means. And then hold them accountable to it.