Can atheists convert theists?

[Purple Rabbit]

Nice example EvF. The point is that with that you don't really reject any specific Easter Bunny at all. I'd say that you simply reject the soundness of the proposition on basis of lack of definition, coherence and meaning.

It's still a definition that has some meaning,..

Please observe that no meaning was stated with it. All meaning you ascribe to it is atributed to it by you. In fact you're simply guessing what it could mean based on prior experiences with the concept of Easter Bunny. This might easily end up in fighting windmills.

.. and I can still reject it based on lack of evidence.

Evidence for your own attribution to the concept? That makes no sense. You're rejecting a concept that hasn't been defined. That's saying that X does not exist without a definition of X.

As I said above... if it's unverifiable so what? That doesn't mean it can't be defined as something unverifiable. Unverifiable doesn't mean undefinable.

I am not using the verifiablity argument in my reasoning. And I am not using undefinability in my reasoning. In fact I've pointed out already that definition in terms of the name of a person is possible. The thing that matters is the definition and its coherence to reality.

The fact its definition for the Easter Bunny is unverifiable and there therefore can't be any evidence to support it is why I reject and disbelieve it.

As pointed out, verifiable definitions can be given and unverifiable definitions can be given. You cannot reject existence of the Easter Bunny on basis of an unverifiable definition (that really is just the agnostic stance about the Easter Bunny), you can only reject the soundness of the proposition and hence the sanity of such an evaluation.

If you were told that there lives a guy called Easter Bunny you would have to re-evaluate your position.

That would be a different definition.

Only different from your guessed definition. This is exactly the trap that many religious believers knowingly or unknowingly stage for you: guess my god. It's a moving target like that of tackattack, ever changing colours, always morphing into something else.

You reject the soundness of the proposition, not the existence of any definition of Easter Bunny.

I reject the existence of the definition of the Easter bunny... the definition doesn't have to be perfectly clear... because no definition is - you can always add more detail.

If the Easter Bunny is defined you cannot reject the existence of the definition. If the Easter Bunny is not defined you cannot assess the claim. Guessing definitions only can lead to assessing your own attributions to the words.