Ancient Babylonia - Temples and Rituals

The care and feeding of the gods in the great temples was a matter of daily concern. Elaborate rituals requiring the participation and support of numbers of temple personnel evolved around the daily presentation of offerings, the cleaning of the divine statues' garments, and the purification of the temples. Offerings were provided from the temple's land holdings, endowments by royal and wealthy people, and from occasional gifts such as war booty.
The temple personnel consumed the offerings. Special festivals were celebrated by every cult, the chief being the Akitu or New Year's Festival of the god Marduk at Babylon. This stretched over a number of days and included a stately procession of neighboring gods, such as Nabu to Babylon, and a formal parade of Marduk escorted by the king from his temple to the New Year's house outside the city wall. Failure to celebrate the festival because of political turmoil or other causes was a grave matter and, whenever this happened, it was recorded with great concern in the native histories.
See The Ziggurats
Walled Cities and Temples

Hammurapi's Code reveals that the Babylonians were the creators of the first great "business civilization." Walled Cities were the centers of Babylonian activities. Each city had its own god and its terraced temple. The temple owned land, slaves, animals, and precious stones.
The Temple Bank

The Temple also served as a bank of deposit for the collective savings (the surplus production) of the people. The priest of the temple thus became a businessman and a banker.