I’m born in a northern country belonging to the European Union and living in a country more southern.
The differences are smaller than you would expect. Both countries are christian by nature though in my home country of which I have the nationality almost half of the population are officialy not really christians. Where I live the majority are, at least officially.
Does being a believer or not, having doubt makes one different, in the sense of better or worse? For me absolutely not at all. We’re all human with failures and qualities, good and evil. Not where we differ counts, but what we have in common.
Christians believe in one God, Islamites in Allah and Israelites in YHWH. Those three names are all One and the Same (monotheists). Even agnostics who believe in Fate, the Force or whatever they believe in (a wee bit) or better said are in doubt (agnostics), they do believe in love. Some ideologies like hinduism believe in more than one (polytheists), none (atheists), (polytheists) or everything (pantheists) that makes basically 4 or 5 really different ideologies. Some philosophers may not count agnostics, others may consider pantheism just a special case of polytheism.