Nature for Epicurus was not determined by the gods, but by its own laws.
Hence pleasure was seen by him as the supreme good because all living creatures sought it and shunned pain.
As for death, his maxim on this subject became famous: that it should not concern us, because as long as we exist, death does not, and it does, we don't.
Epicurus had strong friendships with his pupils. After studying the teachings of many philosophers, he began teaching in Mytilini (Lesvos) in 311 BC, and later founded a school at Lampsacus.
In Athens he was said to have been gifted by the local inhabitants with a house and garden in Athens, so much did they admire him and his ideas. This home became known as the Garden of Epicurus, where he was the head of a rather unique and perhaps shocking household, made up of both slaves and free citizens, serfs, courtesans, and housewives, with the the courtesan Leontia both his mistress and his pupil.
Though he believed in pleasure as an ideal, he lived rather in the Stoic fashion, simply and with a simple diet, in no way living up to the image of him as a voluptuary.
He was an immensely prolific writer, with only a small fraction of his output extant, that small fraction including 37 books (though incomplete) from his work 'On Nature', many maxims, didactic letters, the 'Canon', which sets out his theory of knowledge. Although he believed that there were gods, he saw them existing in a transcendent world quite apart from, and indifferent to, nature and human life.
Natural causes he saw in terms of physics, a knowledge that frees humans from fear of the gods and of death. Religion he saw as ignorance, with people under the shadow of fear of the gods, somewhat like terrestrial spies, hovering over their lives.
His ideas about ethics has a materialistic basis, with the supreme good as pleasure, but intellectual pleasures had a higher value than physical pleasures because they were less ephemeral.
A life of philosophical companionship and friendship was the height of pleasure, and source of a calm and harmonious life. Epicurean thought had a major influence during his time and during the early Christian period, though his views concerning gods indifferent to human life was interpreted as atheism (as with Socrates), causing the dissolution of his school in the 4th century AD, well after his death.