That is a promise and promises are broken every day. The longer receivables go uncollected, the less chance there is of them being collected. So, cash flows basically show that money is moving back and forth. There are three sections to cash flows, operating, investing and financing. Consistent cash flow is a measure of liquidity.
Liquidity measures the ability to pay bills.
Bankruptcy happens when bills cannot be paid. You see, while earnings appear to be a measure of growth, or lack of same, accountants can do a lot of number shuffling to inflate earnings. But they can't create cash. So, to figure out just how these cash flows work, let's see what happens to the Balance Sheet. We are spending cash.