An invocation (from the Latin verb invocare "to call on, invoke, to give") may take the form of:
Supplication, prayer or spell.
A form of possession.
Command or conjuration.
Self-identification with certain spirits.
These forms are described below, but are not mutually exclusive.
See also Theurgy.
As a supplication or prayer, an invocation implies calling upon God, a god, goddess, or person. When a person calls upon God, a god, or goddess to ask for something (protection, a favour, or his/her spiritual presence in a ceremony) or simply for worship, this can be done in a pre-established form or with the invoker's own words or actions. An example of a pre-established text for an invocation is the Lord's Prayer.
All religions in general use invoking prayers, liturgies, or hymns; see for example the mantras in Hinduism and Buddhism, the Egyptian Coming Out by Day (aka Book of the Dead), the Orphic Hymns and the many texts, still preserved, written in cuneiform characters on clay tablets, addressed to Shamash, Ishtar, and other deities.
In Islam, invocation () is a prayer of supplication or request. Muslims regard this as a profound act of worship. Muhammad is reported to have said, "Dua is the very essence of worship." One of the earliest treaties on invocations, attributed to a scholar named Khālid ibn Yazīd, has survived on a papyrus booklet dated 880-881.
An invocation can also be a secular alternative to a prayer. On August 30, 2012, Dan Nerren, a member of the Humanist Association of Tulsa, delivered a secular invocation to open a meeting of the City Council of Tulsa. Nerren was invited to perform the invocation as a compromise following a long-running dispute with the City Council over prayers opening meetings. The invocation was written by Andrew Lovley, a member of the Southern Maine Association of Secular Humanists who had previously used the invocation in 2009 to invoke an inauguration ceremony for new city officials in South Portland, Maine.