A matter of Salvation through Christ!
It is very important to know the answer to this question for the real name of Christ leads to Salvation and another name leads to condemnation (John3:18).
"Whoever believes in him is not condemned, but whoever does not believe is condemned already, because he has not believed in the name of the only son of God", John3:18
Christ's true name is a Hebrew name. And it's definitely not the mocking name "Yeshu" meaning"he that is blotted out of the Scripture", a name which Jewish people invented for him but nowadays don't know and realize anymore...
Then there are 2 names left: Yeshua or Yehoshua as some (Jewish) people claim. But which one is his true name?!
Yehoshua however means "God brings Salvation" or "God brings forgiveness of Sin", because that's what Salvation is. Yet it is not God that brought that forgiveness about!
Yeshua means "Salvation" or "he that brings forgiveness of Sin" and "he" being Christ. Since there's only one Christ it's save to say that this "he" is Christ!
God didn't bring about the Salvation, but Christ did as sacrificial Lamb at the cross. He embodies that Sacrifice also by name!
The true name of Christ is Yeshua. And just as important as his true name is to confess him as Lord of God YHWH:
"Confess Christ as Lord and believe with your heart God raised him from the dead and you will be saved", Romans 10:9.
Using the Old Testament name "Yehoshua" actually means you don't confess Christ as Lord of God/sent by God (John17:3) thus you don't believe Christ embodies the needed sacrifice for your sin thus you don't get life eternal:
"This is life eternal: that they know Thee, the one true God, and Christ Yeshua whom Thou has sent", John17:3.
That's how important it is what name you call Christ: his true name Yeshua or other names that mock him or names that deny him as Lord of God YHWH.
Of course the Latin name "Jesus" denies Christ too as Lord of God, because that name depicts him as the trinity godhead, which he is not! Christ is the HighPriest of God; God is not His Own HighPriest!
"So also Christ did not glorify himself in becoming High Priest, but the one who glorified him was God", Hebrews5:20.
If you want to make it personal: use his true name Yeshua when you pray to him directly (John 14:13-14) and praise him too (John5:23)!
Building a relationship with Christ