Libertarianism is one of the main philosophical positions related to the problems of free will and determinism which are part of the larger domain of metaphysics. In particular, libertarianism is an incompatibilist position which argues that free will is logically incompatible with a deterministic universe. Libertarianism states that since agents have free will, determinism must be false.
The positions of those who hold to a libertarian free will position of man are mostly Arminians, Molinists and open theists. For these theologians, God does not determine whatever comes to pass, but rather man acting in true freedom independently of God determines much of history.
Ultimately this view compromises the Creator/creature distinction as it postulates a "source of power" independent of God (that God has no control over). This makes God finite, with man, in a context / reality that somehow is greater than, and encapsulates them both.