Calvin also warned against false miracles:
When we hear that [miracles] were appointed only to seal the truth, shall we employ them to confirm falsehoods? In the first place, it is right to investigate and examine that doctrine which, as the Evangelist says, is superior to miracles. Then, if it is approved, it may rightly be confirmed from miracles. Yet, if one does not tend to seek men’s glory but God’s [John 7:18; 8:50], this is a mark of true doctrine, as Christ says. Since Christ affirms this test of doctrine, miracles are wrongly valued that are applied to any other purpose than to glorify the name of the one God [Deut. 13:2 ff.].
John Calvin, “Prefatory Address to King Francis,” in The Institutes of the Christian Religion, ed. John T. McNeill, trans. Ford Lewis Battles, (Philadelphia: Westminster, 1960), 17.