It is my understanding that Jesus and Jesus’ are both pronounced the same way. Jesus’s, which is pronounced differently, has only in recent years become an acceptable possessive form of Jesus and is spelled differently. In view of this in reading the Bible, Mrs, Eddy’s works, etc. shouldn’t we be pronouncing Jesus’ Jesus rather than changing it to Jesus’s? Here’s what I found on the internet.

“For many years, it was customary to add only an apostrophe in forming the possessive case of a biblical or classical name already ending in a sibilant sound, like “Jesus” or “Euripides.” The final possessive “s” was neither added nor pronounced.”

…[long discushion of related possesive form usage omitted here].

“However, it’s safe to say that if you add an apostrophe plus “s” when writing the possessive form of a name like “Jesus” or “Moses,” then you should add the extra syllable “uz” when pronouncing the name

“But if you write the possessive forms in the traditional way (“Jesus’ name” “Moses’ wisdom”), then don’t pronounce what’s not there.” (grammarphobia.com, Grammarphobia Blog Biblical commentary)