William Lane Craig in the context of "Reformed epistemology"

The Kalam cosmological argument is a modern formulation of the cosmological argument for the existence of God. It is named after the Kalam (medieval Islamic scholasticism) from which many of its key ideas originated. Philosopher and theologian William Lane Craig was principally responsible for revitalising these ideas for modern academic discourse through his book The Kalām Cosmological Argument (1979), as well as other publications.

The argument's central thesis is the metaphysical impossibility of a temporally past-infinite universe and of actual infinities existing in the real world, traced by Craig to 11th-century Persian Muslim scholastic philosopher Al-Ghazali. This feature distinguishes it from other cosmological arguments, such as Aquinas's Second Way, which rests on the impossibility of a causally ordered infinite regress, and those of Leibniz and Samuel Clarke, which refer to the principle of sufficient reason.

The Eternal procession of the Holy Spirit is a theological concept in trinitarianism that describes the relationship of the Holy Spirit within the Holy Trinity. The doctrine of the eternal procession of the Holy Spirit is related to the doctrine of the eternal generation of the Son; however, in Christian theology procession (or spiration) is viewed as being mysteriously different from generation in order to distinguish the Holy Spirit from the Son.

In Western Christianity, the Holy Spirit is viewed to proceed from the Father and the Son. This is in contrast to the Eastern churches, which argue that the Holy Spirit proceeds only from the Father. This issue has led to the filioque controversy and was a large question in the East-West schism. However, despite being affirmed within the Nicene creed, the doctrine of the eternal procession of the Holy Spirit (alongside the eternal generation of the Son) is today denied by some social trinitarians, such as William Lane Craig.

Molinism, named after 16th-century Spanish Jesuit theologian Luis de Molina, is the thesis that God has middle knowledge (or scientia media): the knowledge of counterfactuals, particularly counterfactuals regarding human action. It seeks to reconcile the apparent tension of divine providence and human free will. Prominent contemporary Molinists include William Lane Craig, Alfred Freddoso, Alvin Plantinga, Michael Bergmann, Thomas P. Flint, Kenneth Keathley, Dave Armstrong, John D. Laing, Timothy A. Stratton, Kirk R. MacGregor, and J.P. Moreland.

The Kalām Cosmological Argument is a 1979 book by the philosopher William Lane Craig, in which the author offers a contemporary defense of the Kalām cosmological argument and argues for the existence of God, with an emphasis on the alleged metaphysical impossibility of an infinite regress of past events. First, Craig argues that the universe began to exist, using two philosophical and two scientific arguments. Second, Craig argues that whatever begins to exist has a cause that caused it to begin to exist. Finally, Craig argues that this cause is a personal creator who changelessly and independently willed the beginning of the universe.

Social trinitarianism is a Christian interpretation of the Trinity as consisting of three persons, each person having their own center of consciousness. These persons are united in a loving relationship, which reflects a model for human relationships. The teaching emphasizes that God is an inherently social being. Human unity approaches conformity to the image of God's unity through self-giving, empathy, adoration for one another, etc. Such love is a fitting ethical likeness to God but is in stark contrast to God's unity of being. Those who are often associated with this term include Jürgen Moltmann, Miroslav Volf, Elizabeth Johnson, Leonardo Boff, John Zizioulas, William Lane Craig and Catherine LaCugna.

Social trinitarianism is often in contrast to Nicene trinitarianism, as social trinitarianism generally denies the trinity being defined primarily by the eternal relations of origin.