The Hittites adopted many of the gods of the Sumerians and Old Babylonians. The odd thing about the Hittites, though, is that they seemed to have recognized that all gods were legitimate gods. Whenever they conquered a people, they adopted that people's gods into their religious system.

As far as history is concerned, this has tremendous consequences for the history of the Hebrews. The Assyrians seem to have adopted the same tolerance towards other religions, which allowed the Jewish faith to persist after the Jewish state was decimated by the Assyrians. And the Assyrians seem to have adopted the same tendency to adopt the gods of conquered people, so the Assyrian conquerors of Palestine adopted the Hebrew god, Yahweh, into their religion. This eventually led to the only major religious schism in Hebrew history, the schism between Jews and Samaritans (there are still Samaritans alive today).

The religion of the Hittite people was concerned primarily with ensuring the favor of the local deity, whose in most cases was that of a fertility god controlling the weather. In most shrines he had a family and wife, and the note of a mother-goddess is another indication suggesting an early matrilineal society. With the unification of the country under the kings of Hattush, a centralized religion developed in which the numerous local deities were combined into a complicated pantheon. It became the kings duty to tour the country and officiate at the most important festivals, chiefly during the winter months. A king who allowed his military duties to override that of the gods, which would lead to dire consequences for the Hittite state. Mursilis II is particularly notable for his duty to religion. There exist several prayer at which he addresses the gods at a time when the nation was afflicted with serious plague or epidemic. In these prayers, he pleas that he himself has given no cause for divine anger and though his father has, he begs for the gods to relent and not to punish the innocent with the guilty.

The names of the deities reflect the ethnic diversity of the Hittite kingdom. The oldest of the gods was that of the Hattia, a god who lead the king to victory in battle. Later, especially in 13th century BC under the influence of Queen Puduhepa, Hurrian deities entered the pantheon and the leading Hurrian pair, Teshub and Hebat, were identified with their Hittite counterparts, the goddess taking a subordinate place.

The religion of the Hittites was an amalgam (mixture). It incorporated popular elements of indigenous to central Anatolia with some external influences largely of Hurrian origin. These external influences appealed particularly to the royal court and is most clearly evident in the rock-cut shrine of Yazilikaya. Water was never far from the peoples thoughts, especially in the heat of the summer, and shrines or reliefs at Hattusas is most likely dedicated to the weather god Teshub and thus was the home of his cult.

About 1200 meters to the northeast of the main site of Hattusas is the famous rock shrine of Yazilikaya. There is perhaps a road or at least a Processional Way from the city to Yazilikaya.

The reliefs of Yazilikaya show gods and goddess wearing the horned headdress which was an originally Mesopotamian characteristic emblem of divinity. The most imposing is worn by the weather god Teshub with goddess wearing their own distinctive crowns. The tradition of depicting divinities standing on an animal is of Hurrian origin. An interpretation of Yazilikaya naturally depends on the understanding the shrines purpose, which is continually debated.

Cremation was widespread in central Anatolia. From textual sources it is known to be the funerary custom of the Hittite kings. The ordinary people of Hattusas, however, were either buried or cremated. Funerary offerings were rather smalover from a funeral feast.