If they don't know the One true God, then yes that counts. You'll know them by their fruit.
Well that means literally nothing. Many of the "christians" I know of have produced downright awful fruit, and many of the atheists I know have produced great fruit. Not that the passage ever made much sense, as you can be a
terrible person and still offer a very convincing appearance of being a good person. And not that your criteria helps me much, given that I'm also skeptical of claims to knowing a "one true god".
IIRC:
1 - Everything that begins to exist has a cause.
We have not established this, as we have never observed anything to begin to exist in the sense you use the term. Or do you believe that the universe began to exist
from existing matter? In every case that we observe something "beginning to exist", what we are observing is not new matter, or things conjured from nothing, what we are observing are new configurations of existing matter. Nothing was
created in this sense when I bake a loaf of bread; I merely reconfigured existing matter in a way that suits me. This is very different from the kind of "begins to exist" that the Kalam posits for the universe, unless you believe that the universe came into being from existing matter, which would undermine your point somewhat.
I reject this premise as unfounded.
2 - The universe began to exist
Again, we don't know that this is the case either.
There's always a cause (this is usually a sequence or a combination of causes) for something to begin to exist.
A loaf of bread, an egg, the tides, our lives, the universe as we experience / perceive it.
Here's that conflation again. Again, whenever we observe something "beginning to exist", what we are observing is existing matter being rearranged in a novel manner. Most of us never observe
any "new matter" beginning to exist. I'm not aware of any such examples.