Here is some information about John Calvin, with the sources given.
“John Calvin (born July 10, 1509,
Noyon, Picardy, France—died May 27, 1564, Geneva, Switzerland) was a theologian and
ecclesiastical statesman. He was the leading French Protestant reformer and the most important figure in the second generation of the
Protestant Reformation. His interpretation of
Christianity, advanced above all in his
Institutio Christianae religionis (1536 but elaborated in later editions;
Institutes of the Christian Religion), and the institutional and social patterns he worked out for Geneva deeply influenced Protestantism elsewhere in
Europe and in
North America. The Calvinist form of
Protestantism is widely thought to have had a major impact on the formation of the modern world.”
https://www.britannica.com/biography/John-Calvin
“Institutes of the Christian Religion,
John Calvin’s masterpiece, a summary of biblical
theology that became the
normative statement of the Reformed faith. It was first published in 1536 and was revised and enlarged by Calvin in several editions before the definitive edition was published in 1559.
The first edition, written in Latin and published in Basel, where Calvin was in exile, included a dedication to the French king Francis I. Calvin intended his work to be a statement of French Protestant beliefs that would refute the king, who was persecuting French Protestants and incorrectly calling them Anabaptists (radical Reformers who wished to separate the church from the state). It consisted of six chapters that discussed the
Ten Commandments, the
Apostles’ Creed, the
Lord’s Prayer, the sacraments of Baptism and the
Lord’s Supper, disputed sacraments, and Christian liberty. Most of the themes of Calvin’s mature thought were contained in the first edition.”
https://www.britannica.com/topic/Institutes-of-the-Christian-Religion
“Calvin’s influence has persisted not only in the Reformed churches of
France,
Germany,
Scotland, the
Netherlands, and
Hungary but also in the
Church of England, where Calvin was long at least as highly regarded as among those
Puritans who separated from the
Anglican establishment. The latter organized their own churches,
Presbyterian or
Congregational, which brought
Calvinism to
North America. Even today these churches, along with the originally German
Evangelical and Reformed Church, recall Calvin as their founding father. Eventually Calvinist theology was also widely accepted by major groups of
Baptists; and even
Unitarianism, which broke away from the Calvinist churches of
New England in the 18th century, reflected the more rational impulses in Calvin’s
theology. More recently Protestant interest in the social
implications of the
Gospel and Protestant neo-orthodoxy, as represented by
Karl Barth,
Emil Brunner, and
Reinhold Niebuhr, reflects the continuing influence of John Calvin.”
https://www.britannica.com/biography/John-Calvin/Theology
Use caution when reading undocumented slander of highly regarded men of God out of the past.