 Calvin 's theology was not without controversy . Pierre Caroli , a Protestant minister in Lausanne accused Calvin as well as Viret and Farel of Arianism in 1536 . Calvin defended his beliefs on the Trinity in Confessio de Trinitate <unk> <unk> P. Caroli . In 1551 Jérôme @-@ Hermès <unk> , a physician in Geneva , attacked Calvin 's doctrine of predestination and accused him of making God the author of sin . <unk> was banished from the city , and after Calvin 's death , he wrote a biography which severely maligned Calvin 's character . In the following year , Joachim Westphal , a <unk> @-@ Lutheran pastor in Hamburg , condemned Calvin and Zwingli as heretics in denying the eucharistic doctrine of the union of Christ 's body with the elements . Calvin 's <unk> <unk> et <unk> <unk> de <unk> ( A Defence of the Sober and Orthodox Doctrine of the Sacrament ) was his response in 1555 . In 1556 Justus <unk> , a Dutch dissident , held a public disputation with Calvin during his visit to Frankfurt , in which <unk> defended free will against Calvin 's doctrine of predestination . Following the execution of Servetus , a close associate of Calvin , Sebastian <unk> , broke with him on the issue of the treatment of heretics . In <unk> 's Treatise on Heretics ( 1554 ) , he argued for a focus on Christ 's moral teachings in place of the vanity of theology , and he afterward developed a theory of tolerance based on biblical principles . 
