It was based on 42 hieroglyphics, some of which were used interchangably. This written language was formed around 3100 BCE, the same time the Pharaohs began to rule, and it lasted until 400 CE, at which time Egypt adopted Coptic, a Greek-based alphabet, and then Arabic (Denault 5).
Ancient Egypt was not based on a set of strict religious beliefs, their ideology was more of a "cult" with regular "practices," duties performed to maintain the favor of the gods. These took place at centers of worship and focused on an "image" of the god, a statue to which they performed sacrifices and rites (Monet 1-5). More will be discussed about Egyptian beliefs concerning the soul and afterlife in the "Heaven" and "Underworld" sections.
Carpenter, Chris, Jennifer Taylor, Kathleen Strachan. "Geography and Agriculture: The Ancient Egyptian Culture Exhibit." Minnesota State University E-Museum. 2003. http://www.mnsu.edu/