When you put money into assets such as stocks, bonds and investment properties you can earn money or income from them. Liabilities are things that cost you money. In addition, you have many other expenses such as loan repayments, insurance, registration, running and maintenance costs. The rule is that if you want to get rich, put your money into income earning assets. This doesn't mean not to buy a home or car - just think don't think of them as assets.
Lets look at the cash flow of the rich, middle class and poor.
Everyone has living expenses but the poor spend all of their money on them. The middle class tend to spend most of their money on liabilities such as credit card debt, personal loans and mortgage repayments. While the rich also have living expenses and liabilities they focus their money on purchasing income-producing assets. Wealth is not so much about your level of income but your pattern of spending. Even people with relatively high incomes can easily find themselves struggling or broke.