True Christian
Well, when looking for a true Christian, someone who actually believes, there are a few things to look for.
1) Christ. I mean actually knowing him. Even if you are new to the religion. Jesus Christ is to be more than just a name. He's to be your savior, redeemer, comfort, father, and friend. If you don't know Christ, and what he did for you, you are not a Christian.
2) Change. There's an expression in the world of Christians. If you are "saved" you recognize your sin and God's ultimate power, and the divide between the 2 of you. A Saved Christian is someone who strives to be more like Christ. And they strive to love others sacrificially, they strive to turn away from their sin (anything against God's commands)
3) Difference. There seems to be something different about Christians, true Christians. Maybe you might not be able to tell what it is. But when you have eternal hope in life and confidence that you have God on your side, you tend to act differently than the rest of the world. In fact, the Bible calls for Christians to be set apart from the rest of the world.
I hope this answers your question! You can contact me if you have any more. :)