Four Noble* Truths
After attaining enlightenment under the Bodhi tree, the Buddha became aware of certain profound truths concerning the nature of life. These are known as the Four Noble Truths and form the essence of the very first sermon. It was delivered to the five ascetics who were his former colleagues at Isipatana (now Sarnath), near Benares
The Four Noble Truths are:
According to Buddha, one of realities of life is that all beings who are caught up in the cycle of existence are subject to dukka.
The Pali word dukkha is loosely translated as ‘suffering’. Although in ordinary usage dukkha means suffering, pain, sorrow, misery, in the First Noble Truth, it has a much deeper and wider meaning, which includes ideas such as unsatisfactoriness, dissatisfaction, frustration, separation, and emptiness. Dukkha permeates our very existence, affecting our body and mind. The body is affected by old age, sickness and death, while the mind is affected by such factors as separation from things and persons one likes, not getting things one desires, being in unpleasant circumstances, etc.
The unsatisfactory translation of the word dukkha as “suffering” has led some people to regard Buddha’s teachings as pessimistic. First of all, Buddhism is neither pessimistic nor optimistic. It takes a realistic view of life and the world. It does not promise you a life in an everlasting paradise nor does it frighten you into accepting some kind of blind faith.
One may ask, ‘what about happiness?’ According to teachings of the Buddha, true happiness is found within, not in external objects such as wealth, power, honour, or selfish love. A little reflection will show that these forms of happiness do not last as they are subject to change. For example, we may enjoy a holiday on a paradise island, but when it is over and we are back to face the daily work and routines, we are left with dissatisfaction.
The Second Noble Truth
The principal cause of dukkha, the Buddha said, is due to deep-rooted desires or craving (tanha)) within us. These desires can take many forms; desire for sensual enjoyment, desire for material gain and achievement, desire for continuation, and even desire for self-destruction.
The original text is as follows:
"It is this 'thirst' (tanha) which produces re-existence and re-becoming, and which is bound up with passionate greed and which finds fresh delight now here and now there, namely, thirst for sense pleasures (kama-tanha), thirst for existence and becoming (bhava-tanha) and thirst for non-existence (vibhava-tanha)".
It is this deep-rooted craving that results in our continued existence in the cycle of birth, death and re-birth (samsara)
For more details see The First and Second Noble Truths
The good news is the cessation of dukkha. This state is Nibbana (Nirvana in Sanskrit), which is the ultimate goal of Buddhist practice.
Nibbana is not a place or a realm of heavenly paradise to be attained after death. Neither is it a state of 'nothingness'. It can be achieved in this life by the total eradication of craving that leads to dukkha. It is to be realised by intuitive understanding of the true nature of our existence. Having eradicated the causes of dukkha, one who has attained Nibbana experiences a state of permanent peace and happiness, and the cycle of existence is brought to an end.
Nibbana cannot be described in terms of our normal experience, which is so limited.
The Fourth Noble Truth
The Fourth Noble Truth is the path that leads to the cessation of of dukkha. This is a set of guidelines to be practised in our daily lives that will liberate us from being driven by our cravings and eventually lead to the realisation of Nibbana. This is the Noble Eightfold Path, also known as the Middle Path, which avoids two extremes: one extreme being the search for happiness through the pleasures of the senses, the other being the search for salvation through self-mortification, which was a common ascetic practice during the time of the Buddha.
* Noble - so called because it was revealed by the Buddha