Not so much the world going mad, as the world growing up and seeing reason I think, Sammo. And, whilst it might upset you Sammo, that does not necessarily mean that will upset the majority. In all countries, there is a growing cohort of people with different faiths, or none. It is entirely appropriate that oaths and promises, especially when related to state actions, are open and inclusive to people of all faiths and none...
An oath to god was never a specific requirement as laid out in the constitution, and those states where it was used have been phasing it out under legal challenge.
From the US Constitution
"The Senators and Representatives before mentioned, and the Members of the several State Legislatures, and all executive and judicial Officers, both of the United States and of the several States, shall be bound by Oath or Affirmation, to support this Constitution; but no religious test shall ever be required as a qualification to any office or public trust under the United States."
Wise old birds that they were, the founders of the US Constitution were very clear that the church and religion had no place in government...