John Calvin in the context of "Protestantism in France"

Reformed Christianity, also called Calvinism, is a major branch of Protestantism that began during the 16th-century Protestant Reformation. In the modern day, it is largely represented by the Continental Reformed, Presbyterian, and Congregational traditions, as well as parts of the Anglican (known as "Episcopal" in some regions), Baptist and Waldensian traditions, in addition to a minority of persons belonging to the Methodist faith (who are known as Calvinistic Methodists).

Reformed theology emphasizes the authority of the Bible and the sovereignty of God, as well as covenant theology, a framework for understanding the Bible based on God's covenants with people. Reformed churches emphasize simplicity in worship. Several forms of ecclesiastical polity are exercised by Reformed churches, including presbyterian, congregational, and some episcopal. Articulated by John Calvin, the Reformed faith holds to a spiritual (pneumatic) presence of Christ in the Lord's Supper.

Presbyterianism (pres-bə-TE-ree-a-nizm) is a historically Reformed Protestant tradition named after its form of church government by representative assemblies of elders, known as "presbyters". Though other Reformed churches are structurally similar, the word Presbyterian is applied to churches that trace their roots to the Church of Scotland or to English Dissenter groups that were formed during the English Civil War, 1642 to 1651.

Presbyterian theology typically emphasises the sovereignty of God, the authority of the Scriptures, and the necessity of grace through faith in Christ. Scotland ensured Presbyterian church government in the 1707 Acts of Union, which created the Kingdom of Great Britain. In fact, most Presbyterians in England have a Scottish connection. The Presbyterian denomination was also taken to North America, Australia, and New Zealand, mostly by Scots and Scots-Irish immigrants. Scotland's Presbyterian denominations hold to the Reformed theology of John Calvin and his immediate successors, although there is a range of theological views within contemporary Presbyterianism. Local congregations of churches that use Presbyterian polity are governed by sessions made up of representatives of the congregation (elders), a conciliar approach as with other levels of decision-making (presbytery, synod, and general assembly). There are roughly 75 million Presbyterians in the world.

Continental Reformed Christianity or Continental Reformed Protestantism is a part of Reformed Christianity within Protestantism that traces its origin to continental Europe. Prominent subgroups are the Dutch Reformed, Swiss Reformed, French Huguenot, Hungarian Reformed, and German Reformed Churches.

The term is used to distinguish these Churches from Presbyterian, Congregational, Reformed Anglican or other Calvinist Churches, which can trace their origin to the British Isles or elsewhere in the world. Notably, their theology is largely derived from the Swiss Reformation, as Switzerland (specifically Geneva and Zürich) was a base for the most influential Reformed theologians of the era. It was inaugurated by Huldrych Zwingli, who formulated the first expression of the Reformed faith. Swiss Reformation was more fully articulated by Martin Bucer, Heinrich Bullinger and especially John Calvin, who became recognized as the leading figure in the Reformed tradition. In the sixteenth century, the movement spread to most of continental Europe, sometimes with the protection of monarchs or members of the nobility, as in the Netherlands, Switzerland, Hungary, some German states, and France.

The Republic of Geneva was an independent city-state that emerged in the early 16th century following its break with both the Catholic Church, the political authority of the Bishop of Geneva, and the political influence of the House of Savoy. Strongly influenced by the Protestant Reformation, and particularly by the work of Guillaume Farel and later John Calvin, the city became a leading center of Calvinism and a refuge for Protestants from across Europe. Politically, Geneva developed republican institutions modeled on some of the Swiss cities, asserting its sovereignty against the Duchy of Savoy and navigating a precarious position between powerful neighbors such as France and the Swiss cantons. From its declaration of independence in 1534 until its annexation by revolutionary France in 1798, Geneva evolved into a prosperous hub of trade, finance, watchmaking, and publishing, while maintaining a distinctive identity as both a fortified “Protestant Rome” and a cosmopolitan republic. The republic was restored in 1813, and briefly existed again before joining the Swiss Confederation as a canton in 1815.

The existence of God is a subject of debate in the philosophy of religion and theology. A wide variety of arguments for and against the existence of God (with the same or similar arguments also generally being used when talking about the existence of multiple deities) can be categorized as logical, empirical, metaphysical, subjective, or scientific. In philosophical terms, the question of the existence of God involves the disciplines of epistemology (the nature and scope of knowledge) and ontology (study of the nature of being or existence) and the theory of value (since some definitions of God include perfection).

The Western tradition of philosophical discussion of the existence of God began with Plato and Aristotle, who made arguments for the existence of a being responsible for fashioning the universe, referred to as the demiurge or the unmoved mover, that today would be categorized as cosmological arguments. Other arguments for the existence of God have been proposed by St. Anselm, who formulated the first ontological argument; Thomas Aquinas, who presented his own version of the cosmological argument (the first way); René Descartes, who said that the existence of a benevolent God is logically necessary for the evidence of the senses to be meaningful. John Calvin argued for a sensus divinitatis, which gives each human a knowledge of God's existence. Islamic philosophers who developed arguments for the existence of God comprise Averroes, who made arguments influenced by Aristotle's concept of the unmoved mover; Al-Ghazali and Al-Kindi, who presented the Kalam cosmological argument; Avicenna, who presented the Proof of the Truthful; and Al-Farabi, who made Neoplatonic arguments.