Judaism is the original and oldest monotheistic religion in the world - the foundation for all other religions that believe in one God. In practice, Judaism includes many texts and observances which are all are based upon the Torah in both it's Written and Oral forms - all revealed through Moses, and given to the Jewish People on Mt. Sinai.
The Infinite Light
by Rabbi Aryeh Kaplan
In order to speak about Judaism, we must speak about man and about life in general. Judaism is, first of all, a way of life, and its depth touches upon the very foundations of human existence. If you truly understand Judaism, you know the ultimate secret of life's purpose.
One of the most important elements of life is purpose. There is an old song that asks, "Why was I born, why am I living? What do I get, what am I giving?" These [and other like-minded] questions has man been asking himself ever since [men and women] first began using their mind.
The most fundamental principle of Judaism is the realization that the universe is purposeful, and that man has a purpose in life. Our sages thus teach us, "A person must have the wisdom... to know why he is and why he exists. He must look back at his life, and realize where he is going." Both man and nature have a purpose because they were created by a purposeful Being. We call this Being God View Book