Girl Guides — the UK equivalent of the American Girl Scouts — recently announced that they would remove the reference to God from their oath, replacing it with a pledge to "be true to myself and develop my beliefs." Some churches have responded by saying that they will no longer let the Girl Guides use them as a free meeting space.
The issue of scouts and the religious nature of their pledges is perennial. The Boy Scouts have been criticized for including in their oath a promise to do their duty to God, while the Girl Scouts have been criticized for allowing members to replace the word "God" in their oath with another word if doing so would "appropriately reflect their spiritual beliefs." And the same disagreements have played out in any number of other countries.
As private organizations that don't receive government aid beyond what other groups receive, I believe the scouts should be allowed to do as they please.
But they should also be aware of what it is they're choosing to do. When it comes to the word "God," people frequently think that it carries a religion-neutral meaning, or that it occupies some ecumenical common ground that is satisfactory to people of all faiths. But it doesn't.
In the first place, many religions aren't theistic. Some religions — Buddhism, Confucianism, and Jainism, for instance — either explicitly reject the existence of God or are simply unconcerned about whether there is such a deity. God or gods, in their view, aren't able to help people achieve enlightenment or virtue. People can only accomplish these things for themselves, no one else can do it for them.
More, religions that are theistic disagree so much about the nature of God (or gods) that the word "God" risks becoming meaningless if it's stretched to cover all of these various ideas. Monotheistic, polytheistic, and pantheistic religions are referring to very different things when they use that word, with some believers even protesting that the Christian idea of the Holy Trinity is inconsistent with monotheism.
Finally, theists don't just disagree about the nature of God, they also disagree about the nature of oaths. Quakers are famous (or maybe notorious) for their refusal to take oaths, which they base on their interpretation of Matthew 5:33-7 and James 5:12.
In other words, it's almost inevitable that you're going to wind up with a pledge that alienates not just atheists and agnostics, but fellow theists and other religious people as well.
Again, as a private organization, the scouts should be free to do just that. But they shouldn't try to defend these pledges as being somehow inclusive or palatable to a great diversity of spiritual and religious faiths. They should be straightforward and accept that they're advocating certain religious ideas while rejecting others, just as religions themselves do. If the scouts want to be religious organizations, then they should be religious organizations.
When it comes to oaths and God, being all-inclusive isn't an option, or perhaps even the goal.