As taken from http://en.wikipedia.org/wiki/Opium_of_the_people#cite_note-0
Religion is, indeed, the self-consciousness and self-esteem of man who has either not yet won through to himself, or has already lost himself again. But man is no abstract being squatting outside the world. Man is the world of man—state, society. This state and this society produce religion, which is an inverted consciousness of the world, because they are an inverted world. Religion is the general theory of this world, its encyclopedic compendium, its logic in popular form, its spiritual point d'honneur, its enthusiasm, its moral sanction, its solemn complement, and its universal basis of consolation and justification. It is the fantastic realization of the human essence since the human essence has not acquired any true reality. The struggle against religion is, therefore, indirectly the struggle against that world whose spiritual aroma is religion. Religious suffering is, at one and the same time, the expression of real suffering and a protest against real suffering. Religion is the sigh of the oppressed creature, the heart of a heartless world, and the soul of soulless conditions. It is the opium of the people. The abolition of religion as the illusory happiness of the people is the demand for their real happiness. To call on them to give up their illusions about their condition is to call on them to give up a condition that requires illusions. The criticism of religion is, therefore, in embryo, the criticism of that vale of tears of which religion is the halo.
Four Noble Truths
Life as we know it ultimately is or leads to suffering/uneasiness in one way or another.
Suffering is caused by craving or attachments to worldly pleasures of all kinds. This is often expressed as a deluded clinging to a certain sense of existence, to selfhood, or to the things or phenomena that we consider the cause of happiness or unhappiness.
Suffering ends when craving ends, when one is freed from desire. This is achieved by eliminating all delusion, thereby reaching a liberated state of Enlightenment.
Reaching this liberated state is achieved by following the path laid out by *"a teacher"* (the Buddha).
Noble Eightfold Path
Viewing reality as it is, not just as it appears to be.
Intention of renunciation, freedom and harmlessness.
Speaking in a truthful and non hurtful way.
Acting in a non harmful way.
A non harmful livelihood.
Making an effort to improve.
Awareness to see things for what they are with clear consciousness, being aware of the present reality within oneself, without any craving or aversion.
Correct meditation or concentration, explained as the first 4.