There are many unbelievers in the world who are millionaires and there are many believers who are poor.
I would add to Willie T's post, all the apostles who left all behind and Christ Himself. There are too many ways rich people can fall into the trap of love of money and begin to rely on their wealth and not God, it seems that is much of what has happened in the west. We have people who dress a certain way depending on which church you attend, you can drive by a church parking lot any given Sunday and see the line-up of certain types of cars. We very much do like to keep up with our neighbors in this way.
IMO, we have placed man's view of success (wealth,power,money) and now say this is also the way God sees man's success (and I am not saying that believers are never blessed by God this way - Abraham, Solomon, etc.), and this is not true. God is much more concerned about our character and integrity then he is about how much wealth we have - thankfully.
1 Samuel 16:7 But the LORD said to Samuel, "Do not consider his appearance or his height, for I have rejected him. The LORD does not look at the things people look at. People look at the outward appearance, but the LORD looks at the heart."