Rippon said:C.H.S. was mistaken in this view.Calvin's theology remained essentially the same through the time of his conversion till death.He did increase in knowledge of course.Theodore Beza knew him for 16 years and said that in essence Calvin's theology was unaltered over the years.(I wish I could find the quote.I read it just yesterday in one of my books.)
Actually John Calvin changed as little as Spurgeon did from his conversion at 15 and a half to his death (at nearly 58)-- it was consistent as could be through the course of time.
I found the quote.It was in my book :John Calvin;Steward of God's Covenant,Selected Writings.The final chapter is from a book Theodore Beza wrote on Calvin's life.
"In the doctrine which he delivered at the first,he persisted steadily to the last,scarcely making any change.Of few theologians within our recollection can the same thing be affirmed."(pages 409,410)