Do Greek Christians truly believe that God exists?

( I totally respect religions and people who are believed in God! I'm just curious to know! As you know some people might consider this question is rude and embarrassing to ask so I have ever had a chance to tell anybody.)

See a translation

I think that if someone is a Christian, then he/she obviously believes in God. Otherwise, why would they be calling themselves Christians?
It's like asking if Atheists really believe that there is no God... of course they do!

But, there may also be people raised and registered as Christians who are not believers. In that case they would either be Atheists or believe in something else, but possibly keep the Christian title because of the tradition.

As far as participating in religious practices is concerned, such as going to the church on major celebrations like the Resurrection, many people do even if they don't believe in God, in order to honour the tradition which dates back almost a couple of millennia, or be with the family, etc.
But most people who do believe, probably practice religion and attend church regularly.