Jews are from the Moon, Egyptians are from the Sun
The first commandment that God gave to the Jewish people in Egypt before the Exodus was to establish the calendar. In order to understand the importance attached to this commandment, we must understand the type of society that the Jews lived in during their exile in Egypt. The Egyptians, along with the rest of the world at that time, worshipped many different gods, each believed to have its own sphere of influence. The only god whom all the Egyptians revered was Ra, the sun god, chief of cosmic deities, from whom early Egyptian kings claimed descent.
The sun does not exhibit any obvious cycles; it remains a constant presence in the sky, year in, year out. In contrast, the moon waxes and wanes, appearing, disappearing and appearing again, cycling between “non-existence” and “existence” every month. Jewish philosophers have explained that the pagan focus on the sun was based on the belief that life too is constant and unchanging – there is no free will, and no possibility of change. The sun symbolizes an unchanging, permanent reality, which for the pagan was a reflection of the deterministic world without moral freedom; life, like the sun, was predetermined and set.
Judaism, however, is predicated on the belief that human beings are morally free and have the ability to choose between good and evil. Life is not predetermined and we are not controlled by our past. The Jewish calendar is therefore focused on the moon, so that the renewal of the moon will act as a reminder of individual renewal through free will. Rabbi Samson Raphael Hirsch explains the insights that we are supposed to draw from the Jewish calendar:
The truth which the calendar teaches forms the foundation stone of our Jewishness, and it is this which differentiates it most sharply from all paganism. The pagan knows no newness, not in the world, not in humanity, not in his gods, nor in the powers he places above men and the world. To him, everything is bound by cast-iron necessity. To him, all todays are evolved from yesterdays, and every tomorrow must with absolute certainty follow from today. Just as he denies creatio ex nihilo, the free creation by the free will of a Creator, so for him there is also no ex nihilo [creativity] in the moral nature of Man, no ex nihilo in the fate of Man. Guilt and evil must forever bring about only guilt and evil. For him, nothing of the godlike freedom dwells in the heart of man, for him no free God reigns in and over the world, everything swims down the stream of blind unalterable necessity, all freedom is but an illusion, everything new is only that which existed in the old!
These ideas are implicit in the Hebrew expressions used for the lunar month and for the solar year. The Hebrew word for month is chodesh, which is related to the word chadash, new. The Hebrew word for year, on the other hand, shanah, is related to the words shinun, repetition, and sheni, second (in other words, not first, not new).