Here is a quote on John Calvin and Calvinism by Karl Barth:

It is not worth while really to become a ‘Calvinist’, but it is certainly almost singularly worth while to become Calvin’s free pupil. If today, after the experiences we have had of his life’s work in its historical shape, and after a renewed return to the sources and origins to which he pointed so insistently, one can think and speak with him only by going beyond him only by thinking and speaking with him in the direction in which he pointed and do so looking back to the days of his work, his struggles and sufferings, in great reverence and genuine gratitude. – Karl Barth, Fragments Grave and Gay, 110.

H/T: Halden

Something lurking here, and worthy of noting, is that Barth is presupposing that there is a fundamental difference between being a Calvinist, and being a student of John Calvin. The latter is what “Evangelical Calvinism” is on about, which like Barth presupposes a distinction between Classic Calvinism and itself.