Ethics provide a guideline for what conduct is right and wrong on a general level for a group of people, a society, or possibly the world. General things would be not stealing, preserving life, taking care of the environment, etc. Morals would be an interpretation of ethics by a smaller group of people or individuals. They would be compromises of ethics or specific bends to ethical conduct based on a given situation. The situations with the furniture and beer would be based on moral reasoning. They are specific situations that are unethical, stealing, but they are reasoned to be morally correct or morally incorrect based on various factors that each individual values.
Regardless of ethics or morals, both situations are ultimately illegal based on laws created by the US government and its citizens. No court would ever see the beer or the furniture as a gift, especially since they are goods that were on sale and you have no proof of purchase or ownership. That alone should be enough to convince you to go back and pay for the item regardless of your moral reasoning. As US citizens you have agreed to the laws of country and are expected to abide by them. If you think the legality of the situation is in question you have the power to try and change the law through appropriate action, but since this is a democracy, it is governed by the people and not you alone, you may find it difficult to change the law. If you are unhappy not being a dictator then maybe you should go to a country with laws that you can abide by or you should go start your own country somewhere else.
If you do find yourself responsible enough to break the law and steal, then you are responsible enough to face the consequences and should turn yourself in for theft. People usually do not do that though because the penalty is greater than the price to have paid for the good in the first place or they are just inherently unethical people.
So the whole point is you should go back and pay for the furniture or beer.
*NOTE* For people that live in other countries there are probably methods to change the law where you live and your government may work differently, but as citizens of that country you also have agreed to abide by the laws.
*On a side note* There is the classical moral/ethical dilemma of what to do if a person you love is sick and will die without proper medication, but you cannot afford the medication and your only choice is to steal it. Ethically and morally this could be confusing because of conflicting ethics with stealing and preservation of life and then the whole legality of the situation. Ideally, I think the best choice is to steal the medicine and give it to your loved one, then go turn yourself in for stealing the medication. This would satisfy ethics by preserving life and then holding yourself responsible for stealing.
