Now, I just gave you two groups who claim to "believe in Jesus" and asked if they are included in your "us all". Now it appears that your "us all" does not include some who do indeed claim to "believe in Jesus".
So there seems to be a line that you do indeed draw as to who "us all" are even among those who claim to "believe in Jesus". Now the question becomes, where do you draw that line when making the claim that Jesus wanted "us all" to be one?
Jesus’ words mean what Jesus meant. If someone thinks Jesus’ words include Mormons and cults, then it’s up to them to prove that’s true.
However, I do think the words mean what they mean. Let’s say that ‘believe’ means XY. Therefore, it doesn’t matter what else is true. If a person XYs, then they are one of the ones Jesus was talking about. Regardless of the group they were affiliated with at the time they XY’d, OR the group they affiliated with after they XY’d.