First of all, your topic is not correctly written, it looks as if you meant to say: why can't I access a casino while my country isn't blacklisted? So make a change in that

This might be for diverse reasons to which are uncertain since we ain't leaving in your country to know the etiquettes of the whole place over there but I'll say as much as I know: 1)I don't think a religion can project a Prohibition on casinos online apart from the ones in the stalls around the community. 2) I don't know why a religion should interfere in issues that aren't in affiliation to them .3) why would they choose to allow the lincensed ones to stay?this simply means they're not against casinos but against not been registered and licensed, are you getting my point or is it totally different??
Please make a clear illustration to your question ( I know you've gotten several replies but I'm not really certain of what to say cus you haven't explained anything properly)
Some religions are just too strong and it is also possible for them to ban a website aside from the physical ones. We may think that why will they ban gambling? But, they ban it because they can see it as a forbidden act. There are religions that are like that which they are really sensitive on some things.
There are even religions that bans some type of foods and I don't think there was a problem with the op's title. What he mean is that there are gambling that are allowed and there are also gambling that are not allowed in his country. Usually non registered or non licensed gambling are considered to be illegal by the governments.