1. There is good money and bad money - "All seekers of truth know bad money can never do good deeds and refuse soiled funds from any source. Nor can good money used wrongly reap right results. Ill-gotten money is never well-spent, but has a curse upon it." ( Here think about people, for example, who win millions in a lottery. Most end up being destroyed by it or or losing it all rather rapidly)
2. Money is a form of prana or energy - "Yes, there is such a thing as good and bad money, because, after all, money is energy. Why is money energy? Money gives energy. Money is power. Money is a form of prana captured in paper, in silver and most importantly in gold."
3. Bad money does bad things - "Bad money does bad things--money earned through selling arms, drugs, taking bribes, manipulating divorce, performing abortions, gambling, fraud, theft--money gained through a hundred dark and devious ways. Bad money issues from a bad intent which precedes a wrongdoing for gain or profit. That is bad money. When spent or invested, it can be expected to bring unexpected negative consequences. " (Consider issues which emerge when one family member manipulates the will or estate of another family member who soon dies). Sivaya Subramuniyaswami adds this: "Bad money provokes bad acts which are long lasting, and it sours good acts within a short span of time within the lives of the people who receive it."
4. Bad money can't be purified - There are some who believe, erroneously, that bad money can be purified by being accepted and put to good use such as building temple or as a donation to noble cause. Here's the writer's response to this thinking: "Some postulate that using bad money for good purposes purifies it. That is a very unknowledgable and improper concept, because prana, which is money, cannot be transformed so frivolously....
Money cannot be laundered by religious institutions. Money cannot be legally laundered by banks. Money cannot be laundered by individuals."