Presumably you meant "who believe there are."
No, it seems that I meant to type "who believe that there are", and missed the "there". Typos do happen.
But you are mistaken, for my definition does not exclude those who believe there are sufficient reasons to reject the existence of God. Consider the two compatible claims:
- There are insufficient reasons to believe in God.
- There are sufficient reasons to reject the existence of God.
These are perfectly compatible. Similarly, I can say that there are insufficient reasons to believe there is an elephant in the room, and there are sufficient reasons to reject the existence of an elephant in the room.
I might have phrased it a little vaguely in my post - sorry, it was late and I am in a lot of pain right now - but I did address this in my post. The argument was not between sufficient reasons against God existing and sufficient reasons for God lacking.
As I said: "...sufficient reasons to reject the existence of God,
topping sufficient reasons to believe in God."
Meaning: there are both sufficient reasons for and against God, and the person, for whatever reasons, prefers the against side. Such a person would not think there are no sufficient reasons for God, and still be an atheist.
Beyond that, I don't think the claim that infants are atheists is even remotely tenable.
If you consider the concept of "holding a (positive) belief" as a component of the term in question, and consider that "holding a belief" is limited to entities that are
capable of holding beliefs - conscious living beings - then there are only two potential options: one either has such a belief, or one does not. Atheists are those people who do not have such a belief. Babies, if they don't have such a belief, fall into this group.
You wanted to know what it was that all atheists have in common. That is it. Why do you still refuse?