(1) suffering (duḥkha), (2) accumulation (samudaya), (3) cessation (nirodha), and (4) the path (mārga).
Suffering is the essence of repeated birth and death through the six life-journeys; accumulation of afflictions, especially thirsty love (tṛṣṇā), is the cause of suffering; cessation of suffering reveals nirvāṇa; and the Eightfold Right Path is the path to nirvāṇa.
As a condensed version of the Twelve Links of Dependent Arising, the first two truths reveal that, for continuing the flow of saṁsāra, the cause is accumulation of afflictions and the effect is suffering; the last two truths reveal that, for terminating the flow of saṁsāra, the cause is taking the Eightfold Right Path and the effect is cessation of suffering, realizing nirvāṇa.
Here is a simple way to interpret the Four Noble Truths:
1 Life can stink
2 Because of our ignorance,
3 But there’s a way to make it smell good.
4 Here’s how.
1. Dukkha exists - unsatisfactoriness, suffering, discontent, stress (to be Investigated)
Nothing lasts forever. When you understand this it makes it easier to not be so attached to what you're experiencing. So when you're experiencing something you think is bad, you can relax in the knowledge that nothing bad lasts forever. Similarly, when you're experiencing happiness you can also realize that nothing good lasts forever. Why would you want to do that? Because it helps you to be more aware of how you're reacting to your experiences at all times.
2. The cause or origin of dukkha is craving (tanha-lit. thirst) or clinging (to be Abandoned)
Craving sensory stimulation, craving existence, and craving non-existence give rise to the "continuity of being" (the tendency to confuse reality with your perception of reality), and with it its attendant suffering. Say you want something and you don't get it--you'd get sad or frustrated. But say you want something and you do get it. Eventually you'll get bored with it and you'll start wanting something else. And so you start all over again. And that's a bummer.
3. Dukkha ceases with the relinquishment of that craving (to be Realized)
You can end eternal suffering by ending the craving that leads to the continuation of suffering. Remember that suffering is caused by endlessly wanting what you can't have. So if you can stop this endless wanting, you won't suffer anymore. That's not to say that you won't ever feel pained or sad (or happy or ecstatic) ever again. It's just that it won't be part of an endless cycle of wanting--not getting--being sad--wanting again.
4. The path leading to the cessation of dukkha is the Noble Eightfold Path
So how do you end eternal craving? Just live by the ideals of the Noble Eightfold Path. The Path is grounded in a program of meditation. It delineates a plan of self-discipline regarding ethical conduct, mental discipline, and wisdom. The Path avoids two extremes--the pursuit of complete and ultimate sensory pleasure, or the pursuit of utter self-denial.