Religion and European constitutions

[Deesse23]

Looking up the three constitutions you mentioned:

Germany: mentions it in the preamble in the phrase "Conscious of their responsibility before God and man," which can be interpreted several ways, for instance, as two separate sources of obligation. Perhaps it's more rhetorical than anything else. Also in the context of "So Help me God" in the oath of office. Not ideal that it's treated as an integral part of the oath of office, but that's about it.

Preamble, exactly. That means, god, or the christian belief, is factually not part of the constitution. The constitution starts with article 1, after the preamble.

Oath of office: "So help me god" is not mandatory. When Olaf Scholz was sworn in, he didnt utter those words. Look it up on YT.

The interpretation of the german supreme court is that the founding fathers stated the source of their own principles on which they founded the constitution. Those (christian) principles are not, and can not be the foundation of the german constitution, because otherwise the paragraph of religious freedom would be contradictory, according to the german supreme court.