Everything in this world is vanity, but that does not mean you should not enjoy what life have to offer. Money is very important if you are to live a quality life.
Yes, the rich and the poor will both end up in the grave. But that does not mean you should not make and enjoy money. Whether or not you eat well, or you eat badly, the dirty plate will still end up in the sink. That does not mean you must stop eating food!
Do what you have to do legally to make money, it is very important as long you are still on this earth.