A "prayer of invocation" is used to call a deity or spirit to be present in a gathering of people. It is common for religious or formal gatherings to commence with a prayer of invocation by a pastor or another leader of the gathering.
When shared at the beginning of a gathering, the prayer of invocation is intended to invite the presence of a deity throughout the meeting. Church ceremonies sometimes include an invocation as well. Such prayers may also occur at different points throughout a gathering. In these cases, the purpose is often to call on the help or support of a deity or spirit.