Karen King’s draft paper on Jesus’ wife, and the Harvard Divinity School’s web site on the subject, both have a minor grammatical problem: the English title given to the gospel fragment. They style it as The Gospel of Jesus’s Wife, i. e., the possessive form of “Jesus” is made by adding an apostrophe – “s,” rather than simply an apostrophe.
I would respectfully suggest that they change this in the final version. It should be styled “Jesus’ wife.” Saying “Jesus’s wife” is just too awkward.
The consensus of grammarians seems to be that you should write it as you would speak it, avoiding awkward usages. Even Strunk and White, who say to follow the rule about apostrophe – “s” “whatever the final consonant,” make an exception for Jesus. Already, I notice that The Christian Post and Reuters have “corrected” King’s and the Harvard Divinity School’s usage in reporting the story of this gospel. This form of the possessive of “Jesus” (without the additional apostrophe – “s”) has a firm precedent in popular literature; try singing the hymn “All Hail the Power of Jesus’ Name” as “Jesus’s Name.”