How do you call someone who is religious only because it makes them feel happy?

[Haipule]

Got to go with "xtian hedonist", though it does stretch the imagination for anyone to actually find it pleasurable.

Maybe we should call them a Whateverist! 

[Whateverist]

Hey, that one's taken. It means I'm open to the truth, whatever it turns out to be. (Still atheist so far.)

[Magilla]

. . .

I guess I didn't express myself clearly enough. I referred to people who practice religion out of comfort. I wanted to include polytheistic religions too.

It depends upon how loosely you are using language.
On the proposition: "A god exists" a person may agree, (ie. believe), or they may not.
On the proposition: "More than one god exists" a person may agree, (ie. believe), or they may not.
On those propositions, there is no middle ground, a person believes or they do not.

When in agreement, a person is a theist, ({ believe in a god } = { theist } is a tautology).
When not in agreement, a person is NOT a theist, (that is also a tautology).
When a person is NOT a theist, they are an atheist, (ie. just another tautology).

To be an atheist requires no effort. I read in this thread that some people were apatheists, ie. atheist by virtue of not giving a damn.
On the other hand, a person with a bit of effort can arrive at the atheist position, by some consideration of the evidence and arguments, pro and con.
If a person is unsure whether or not a god exists, they are NOT theists, and so are atheists. These people are agnostic atheists.
Being agnostic is about knowledge. One can be an atheist by virtue of not being convinced by the evidence and arguments, pro and con.
The agnostic has insufficient confidence to say that their level of knowledge confirms a justified belief in a god or gods.

Some other atheists are convinced that the evidence and arguments pro and con, are sufficient for them to to accept that: "No gods exist."
These latter people may be called strong or positive atheists.

So the question you need to be asking Die Atheistin is: "If you asked these people that you know . . . 'Do you truly believe in the existence of any god or gods'?"
then if the answer is: 'YES', it is tautological that they are theists.
If the true answer is: 'NO or I DON'T KNOW FOR SURE", then they must be atheists.

Going to church purely because it makes one feel good, is not an instance of true belief in a god or gods, therefore it indicates atheism.

[Cyberman]

"Chasers of the Joneses"? In it because all the "cool" people are in it?

AKA hobby xtians, or RINOs - religious in name only.

[GUBU]

That type of religious people, who don't really believe in any God, but imagine that one or more exist because it gives them comfort. Are they atheists who don't wanna leave the religion? Is there a name for this exact type of people?

I'd call them intermittently happy.

Oh, and your "imagine that one or more exist" encapsulates belief pretty well because belief is when you take something to be true when you either have insufficient evidence, or the evidence points to that thing being false. Nobody believes in things with sufficient evidence. So the people you describe are agnostic deists or theists, depending on what attributes they give their gods.

[Haipule]

Hey, that one's taken.  It means I'm open to the truth, whatever it turns out to be.  (Still atheist so far.)

Sorry, I couldn't help myself! It was like this HUGE meatball I had to eat. I could not control it. I'm so going to hell!

[Whateverist]

Hey, that one's taken.  It means I'm open to the truth, whatever it turns out to be.  (Still atheist so far.)

Sorry, I couldn't help myself! It was like this HUGE meatball I had to eat. I could not control it. I'm so going to hell!

Oh, okay.  See you there.

[downbeatplumb]

That type of religious people, who don't really believe in any God, but imagine that one or more exist because it gives them comfort. Are they atheists who don't wanna leave the religion? Is there a name for this exact type of people?

The majority of believers.

Most I feel, don't really know what they are supposed to believe in but believe in something that they can live with.

The ones who read the holy books are the intolerant arseholes.

[c172]

I just finished a veggie sausage English muffin with American cheese. Stahp it with the meatballs!

[Succubus]

I just finished a veggie sausage English muffin with American cheese. Stahp it with the meatballs!

Wot. Are there no food banks where you live? I make sausage from the leftover venison.