One of the problems is that Calvinism is often used as a shorthand for the Reformed denominations but not all Reformed Christians adhere to the teachings of Calvin. Compare for example Arminanism with Calvininism.



In a sense Calvinism did take over Lutheranism. Calvin was regarded as one of the greatest reformers during his time and was a good friend of Melanchthon who became one of the great systematic Lutheran reformers after the death of Luther. It was only after the Consensus Tigurinus where Calvin reached a compromise with the remnants of Zwingli over the issue of the Eucharist that Calvin was no longer considered a bridge between Lutheranism and Reformed Christians.

That is what can be said of the time when Calvin was alive but his work helped to shape something very different from Lutheranism. The difference is best seen in the way they tried to build their congregation. Luther allied himself with the nobles while Calvin tried to make a model out of Geneva. This model is proved to be a lot more mobile and worked better in small social circles. Luther dreamed of reforming the whole Catholic Church while Calvin focused on encouraging small splinters and evangelical refugees from all over Europe to keep their faith. The idea of a mostly self-sufficient congregation that depended on local support proved to be far more easy to export than to build ties to any rulers and convincing them first.



Theologically speaking, Calvinism did not really overtake Lutheranism although it can be argued that most Lutheran churches do not really adhere to their doctrinal views on the Eucharist and quietly adopted a more Calvinist approach over time. Similarly, many Calvinists, for fear of being attacked for their beliefs in predestination, usually do not emphasise this contentious part of their doctrine.