“He held to some of the tenets of the Catholic faith, one being infant baptism”
So did John Wesley, btw. How do you know if a person was born again? Its disgraceful that armchair theologians can write off people simply because they disagree with some nonessential doctrine. Calvin and other reformers literally put their lives on the line to help spread the gospel going against the powers that be in their time.
I am not a Methodist and do not accept infant baptism. I believe in baptism after a person has believed and has received Jesus for their salvation. If you want to believe that John Calvin was saved through infant baptism, then that is your choice.