The five precepts are the most fundamental rules that Buddhists should follow. They are: not killing, not stealing, not engaging in sexual misconduct, not lying and not consuming intoxicants.
If you receive the precept against killing and constantly refrain from killing, you will be rewarded with longevity. You will live a long life. Why is it that some people have long life spans while others have short life spans? Those who had upheld the precept against killing are rewarded with a long life, while people who liked to kill have the retribution of short lives.
Why should we observe the precept against stealing? It is because stealing causes others to lose their wealth. What is stealing? It is covertly taking away properties and materials belonging to others. What’s the retribution for stealing others’ things? The retribution will be that of not being able to hold one's own wealth long. For example, someone may be rich, and all of a sudden that person gets robbed.
Sexual misconduct, lying, and taking intoxicants are similar. For instance, someone who does not observe the rule against sexual misconduct might have affairs with others’ women. In the future, that person's own wife or daughter will also be prostituted by others. Those are the kinds of retributions that will happen.
As to lying, if we don’t cheat people, we will not be cheated.
Someone may complain, “I have never cheated anyone in my life. Why is it that many people cheated me?” Didn’t I just say that the matter of retribution is not limited to one lifetime? It spans three time periods: past, present, and future. You may not have cheated anyone in this life, but do you know how many people you had cheated in your previous life? “I don’t know.” You don’t know? So it may be fitting that people cheat you now.
A person may not have intended to boast, but it's very easy to tell a lie without even realizing it. Telling lies can happen very fast. A lie comes out before we know it. For instance, someone may ask a person, “Have you stolen something?” The person may reply, “I didn’t” without even stopping to think even if he did. If in fact, the person stole, then, by denying it, he commits the offense of lying on top the offense of stealing.
A little wine doesn’t hurt. However, if people drink a lot they will become confused and do crazy things. That’s why drinking wine is prohibited in Buddhism.
If we were to elaborate, the five precepts encompass many principles. The main point is that when we make sure our hands do no killing, we must also be sure that our minds do not entertain any thoughts of killing. Then we are truly upholding the precept against killing. The same applies to the precept against stealing. When our hands are not stealing, our minds must also be free of thoughts of stealing. Regardless of the value of objects, if someone uses something or takes something stealthily without getting permission, then that is considered to be a violation of the precept against stealing.