"Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important."

[Peh]

Jumpin said:

Atheism as "lacking belief in God" is an incredibly poor definition due to its broad/wishy-washy nature; it's fairly useless when defined like that. As Neil Degrasse Tyson put it, you don't define someone as an "aGolfer" because they don't golf. In addition, one who lacks belief in God or gods could be a deist agnostic rather than an atheist; since agnostics don't deny the existence of God or Gods, but they don't believe in them either.

The most broadly accepted definition of Atheist is "One who denies the existence of God or gods."

This is a useful definition, it is precise, and there isn't confusion about conflating its meaning with anything else.

No. 

By going with "atheists deny the existence of a god" or even saying that they believe god doesn't exists presumes that god  actually do exists. In which case has to be defined which god exists.

By saying "I don't believe in god" can be seen as " I am not convinced by your concept of god".

That is also the official definition of the word atheism. The one you are using is one that is being used mainly by apologetics who also call atheism a religion. That is simply wrong.

 

Agnosticism is also used incorrectly. Agnosticism says 2 things. 1. We don't know if a god exists. 2. We cannot and we won't know that a god exists. Meaning its impossible to answer that question. Agnostics are also considered atheists, because they are not believing in one.

 

And a deist is someone who believes in a god who kickstarted the universe and been absence ever since. Meaning whereas theist believe god interacts with our world, a deists on the other hand says he doesn't.

So I don't know what you mean by "deist agnostic".