It seems to me like it still requires you to just believe the same amount of stuff, still makes demands on what to do, what to think, etc.
So basically the whole argument strikes me as: it walks like a duck, it quacks like a duck, but it's fish so you need to educate your taste buds
At any rate, "no other relationship depends on belief in existence," seems to me like actually the right answer. That relationship depends on... religion. It's begging the same questions as before.
For the relationship with Jesus to work like that (or indeed at all), you have to first believe:
1. that he existed (a relationship with a non-existent entity isn't a real relationship)
2. that he did resurrect and ascend to heaven (a relationship with somebody who died, stayed dead and _is_ dead, well, again isn't much of a relationship)
3. that at least most of the accounts of what he said, did, etc, and the interpretations thereof are factually correct (otherwise you're probably not really doing what he wants in that relationship)
4. that being in that relationship actually does anything other than being a waste of your time and neurons. I.e., pretty much that yes he is the Son Of God, or at least otherwise special to God, you're going to get this or that privilege for being in that relationship, or this or that punishment after death for refusing it, etc. (This isn't technically needed for _a_ relationship to exist, but I've yet to see any theists who don't expect this part to be a part of their "relationship with Jesus". Nobody does it just so Jesus doesn't feel lonely

)
Etc.
To have that kind of "relationship", it's a pre-requisite to swallow the rest of the religion first.
To illustrate the point briefer: If you don't believe in the Christian religion, there is no Jesus to have a relationship with. It's as simple as that.
It's like saying "it's not about a car, it's about _driving_". Well, yes, but as long as the car is still an implied part there, wth difference does it make? Just shifting the focus a bit doesn't make that requirement disappear.
Or even shorter: the whole "it's about the relationship" thing is a piss-poor word game. Nothing more.