In Twelfth Night, we get two kinds of references to the deity: God and Jove.
“God” gets 18 uses by Feste (5 uses), Viola (2), Antonio (2), Maria (3), Olivia (1), Sir Toby (2), and Sir Andrew (3). These references range from the sarcastic (Viola/Cesario’s doubtful response to Olivia’s beauty–”Excellently done, if God did all” [I.v.226]), to the less than reverent (Maria’s “For the love o’ God, peace!” [II.iii.80]), to the imploring (Olivia’s “God comfort thee!” [III.iv.29]).
On the other hand, “Jove” is used only nine times (in just 6 speeches) by only three characters. Two of those characters (Feste [2 uses] and Sir Toby [1]) also use “God/god” in the play. The remaining character uses “Jove” exclusively.
If you’re thinking this character would be our play’s Puritan, Malvolio, you’d be right.
And his using of “Jove” rather than “God” is completely fitting.
At first, it might not seem so, as Jove is the English derivation of the Roman god Jupiter (Jupiter comes from the Latin “luppiter,” the combination of “lou” and “pater,” the personification of “father”; and it is the “lou” that the English took as “lov,” regaining its old Roman J opening sound.
However, it was not to just the Roman god Jupiter that Jove is linked. Some linguists find a link between “Jove” and Jehovah, the Hebrew name for God in the Bible. And it is in this sense that Malvolio’s use makes sense. He’s not going to call God “God,” as some find this blasphemous. Even in his praise, Malvolio uses “Jove” (“Jove and my stars be praised” and “Jove, I thank thee” [III.iv.164, 168], “it’s Jove’s doing, and Jove make me thankful” [III.iv.70])”.
By Jove, Malvolio will not take God’s name in vain.