Girlguiding is it dropping the phrase "to love my God" from its Promise after a consultation suggested the pledge needed to include non-religious youngsters and those of other faiths.
Instead, girls joining the organisation will now be asked to "be true to myself and develop my beliefs."
The new Promise also asks guides "to serve the Queen and my community" instead of "the Queen and my country".
The Girlguiding movement, which counts over half a million members, have signed a petition calling on The Sun newspaper to stop the use of page 3 topless models.
In a poll of its members, who are aged 16 to 25, 88% called on Sun editor Dominic Mohan "to finally take bare boobs out of The Sun".
Julie Bentley, chief executive of Girlguiding, said: “We are very proud that young women in Guiding are choosing to speak out and play a part in building the society they want to live in.”
The Girl Guiding Association says that the online consultation on the future of the organisation's oath of allegiance will allow them to match their members needs better.
The Girl Guides are considering removing references to God and the Queen from their oath of allegiance as the organisation seeks to attract new volunteers.
Thousands of girls are on waiting lists to join the Rainbows, Brownies and Guides because of a lack of trained volunteers to help run events.
The president of the National Secular Society, Terry Sanderson, said the Scouts' consultation on an alternative oath for atheists was a "move in the right direction".
He also said it would put an end to "unpleasant confrontations" such as that of 11-year-old George Pratt, from Midsomer Norton in Somerset, who was excluded because he did not want to make the Scout Promise in its present form.
Membership of the Scouts has risen during the past seven years from 444,936 in 2005 to 525,364 this year, figures released by the association show.
Since 2002, the number of girls taking part has increased by 69% while more than 50 scout groups catering for young people drawn mainly from Muslim, Hindu and Sikh communities have opened in the last ten years.
The existing Scout Promise contains a vow of allegiance to the God and the Queen .
Alternative versions allow Hindus and Buddhists to use the word "my Dharma" while Muslims can use the word "Allah".
Non UK citizens are permitted to replace the phrase "duty to the Queen" with "duty to the country in which I am now living".
Atheists could be welcomed into the Scout movement for the first time in 105 years, the Scout Association has said.
The movement, led by TV adventurer Bear Grylls, is launching a consultation to see if members would support an alternative Scout Promise for those who feel unable to pledge a "duty to God".
For more than 40 years, versions of the oath have existed for faith groups including Muslims, Hindus and Buddhists, but this is the first time Scouts have considered an adaptation for atheists.
The proposed changes are designed to increase diversity in the movement and enable more young people and adults to join.
Leaders insist the existing Scout Promise - which also contains a vow of allegiance to the Queen - would continue to be used alongside alternative versions.