Kairos

Kairos (καιρος) is an ancient Greek word meaning the "right or opportune moment". It is now used in theology to describe the qualitative form of time. In rhetoric kairos is "a passing instant when an opening appears which must be driven through with force if success is to be achieved." (E. C. White, Kaironomia p. 13)

In theology
In the New Testament kairos means 'the appointed time in the purpose of God', the time when God acts (e.g. Mark 1.15, the kairos is fulfilled'. It differs from the more usual word for time which is chronos (kronos).

In the Eastern Orthodox Church, before the Divine Liturgy begins, the Deacon exclaims to the Priest, "Kairos tou poiesai to Kyrio" ("It is time [kairos] for the Lord to act"), indicating that the time of the Liturgy is an intersection with Eternity.

In The Interpretation of History, Lutheran theologian Paul Tillich made prominent use of the term. For him, the kairoi are those crises in history which create an opportunity for, and indeed demand, an existential decision by the human subject - the coming of Christ being the prime example.

In the Kairos Document, an example of liberation theology in South Africa under Apartheid, the term kairos is used to denote 'the appointed time', 'the crucial time' into which the document / text is spoken.

Many Roman Catholic churches and Roman Catholic schools have "Kairos Spiritual Retreats." In this sense, kairos is adapted to mean "God's time," as per the Bible.

Kairos is also the name of an international Christian prison ministry, which brings the Cursillo method into correctional facilities. Kairos Prison Ministry is an independent and highly ecumenical organization that draws its members and leadership from Cursillo groups and from such Cursillo-derived groups as Via de Cristo, Walk To Emmaus, and Tres Dias.

In rhetoric
Kairos was central to the Sophists, who stressed the rhetor's ability to adapt to and take advantage of changing, contingent circumstances. In Panathenaicus, Isocrates writes that educated people are those “who manage well the circumstances which they encounter day by day, and who possess a judgment which is accurate in meeting occasions as they arise and rarely misses the expedient course of action”.

Kairos is also very important in Aristotle's scheme of rhetoric. Kairos is, for Aristotle, the time and space context in which the proof will be delivered. Kairos stands alongside other contextual elements of rhetoric: The Audience which is the psychological and emotional makeup of those who will receive the proof; and, To Prepon which is the style with which the orator clothes their proof.

Compare the use of kairos in rhetoric to the use of kairosis in literary aesthetics.

Kairos is also the name of "a refereed online journal exploring the intersections of rhetoric, technology, and pedagogy."