The Egyptians believed in a soul that lived on after death, called a ka; they believed that providing for the needs of the ancestors assured safety and prosperity for the living; they believed that the afterlife was very similar to this life, and so they ensured that their possessions were buried with them. These beliefs led to elaborate burial practices, the building of tombs by the rich and powerful, and of course the mummification process.
The ancient Egyptians worshipped hundreds, if not thousands of gods and goddesses. In addition to the many familiar names, such as Isis and Osiris, small towns had their own patron deities. For example, the small town now called Deir el-Medina, the home of the artists who created the tombs in the Valley of the Kings, worshipped a local mountain, which they called Meret-Seger, or "She-Who-Loves-Silence" (very appropriate for the area of the royal tombs!)
In ancient Egypt, the king was called "The Living Horus," after the falcon-headed god of kingship. His son and heir apparent was called "The Horus-in-the-Nest." His dead father was called the Osiris, after Horus's own father. Horus was married to the goddess Hathor, so the Great King's Wife, the queen, took on that role. You may know the king of Egypt by another name-the pharaoh. This word actually means "Great House," or "per-aha" in ancient Egyptian. The name was used by the Greeks, and has come down to us through history.