From Uncommon Wisdom (teachings of Ajaan Pannavaddho), chapter called Purpose:
…We start off with the fundamental basis of Buddhism, the fact that we all experience dukkha or discontent which we are trying to cure. We attempt to cure our discontent by using cause-and-effect methods; in other words, we initiate those causes that we believe will lead to the relief of our suffering. In doing so, we search for causes, or actions, that result in less dukkha and greater contentment. Dukkha can be anything from small irritations all the way up to intense suffering. This is fundamentally what we are trying to remedy. It makes no difference whether we are Buddhists or not, we are all driven by this quest to find happiness.
If we’re wise and we understand the situation correctly, then we might actually choose the right course of action and manage to get the happiness we are seeking. But because our minds are clouded by defilements, we tend to make the wrong decisions. Due to thinking and acting wrongly, we pile up more and more suffering. Failing to understand the correct way to get rid of suffering, we tend to make the same mistakes over and over again. This is the situation that we are in.
We can get into a tangle when we want to get rid of a particular instance of dukkha; we may think if we can only acquire something desirable or get away from something undesirable, all will be well. Sometimes it is not clear to us what the best course of action is because our vision is clouded by our (often subconscious) desires and aversions. But the Buddha has given us the five precepts to help simplify the situation. If we learn and remember the precepts and commit to using them as our guide to behavior, even in the dark we can sense the direction of wholesome action.
In traditional formulation:
I undertake the training rule to abstain from harming life.
I undertake the training rule to abstain from taking what is not offered.
I undertake the training rule to abstain from sensual/sexual misconduct.
I undertake the training rule to abstain from false speech.
I undertake the training rule to abstain from intoxicants causing heedlessness.
Preserve and protect life.
Counter greed by not taking more than we need, or things others may have a claim on.
Do no harm with sexual energy.
Be truthful and careful in speech.
Keep our heads as clear as possible.
How do we apply the precepts in daily life? The truth in a particular moment may be that we are unsure, that we don’t know what to do right now. In that case, if possible, do nothing; we can wait for our perception of the situation and our intentions to become more clear. Sometimes we assume that there’s an imperative to act, but the opposite may be true; we may be facing an imperative to wait until we correctly see the source of our discontent and what we might do to counter it.