Moral relativism? The truth does not change with time and if Calvin was so 'holy', he would have not conspired nor orchestrated the murder of an innocent man.
Moral relativism? HA!
Slavery at one time in this country was legal. According to your logic then every slaveowner who ever existed while it was legal should be condemed to hell. Truth does not change but our understanding of right and wrong certainly does. Besides that, you already pre-loaded the assumption that Calvin "orchestrated a murder". How disingenous of you. So answer the question. Do you blame God for requiring Moses and Joshua to kill the babies of their enemies?