In one of the biggest overhauls in its 102-year history, organisation makes attempt to modernise foundations of promise

God, Queen and country – the foundations of the Girl Guides were trumpeted from the very first days of the organisation's existence in 1910. But now, following a consultation with members, God and country are out – leaving just the Queen.

In one of the biggest overhauls undergone by guiding in the UK, girls will now instead promise to "be true to myself and develop my beliefs". They will also pledge "to serve my queen and community".

The modernising move is aimed at ensuring all girls, religious or not, feel welcome in the Guides.

A vow to love or serve God has been included in the Promise since the Guides began, with members originally pledging to "do my duty to God" before this was changed to "love my God" in 1994.

The change has been lauded as a "hugely positive" development by secular groups.

About 44,000 people responded to a consultation on changing the oath's wording, according to Girlguiding UK. The group still believes girls need space to explore their beliefs and "moral framework", said Chief Guide Gill Slocombe. "We knew that some people found our Promise confusing on this point and that it discouraged some girls and volunteers from joining us.

"We hope that the new wording will help us reach out to girls and women who might not have considered guiding before – so that even more girls can benefit from everything guiding can offer.

"Guiding believes in having one Promise that is a clear statement of our core values for all our members to commit to. We hope that our new Promise will allow all girls – of all faiths and none – to understand and feel proud of their commitment."

The oath now reads: "I promise that I will do my best: to be true to myself and develop my beliefs, to serve the Queen and my community, to help other people and to keep the (Brownie) Guide law."

Girlguiding UK is the largest voluntary organisation for girls and young women in the UK with 546,000 members.

Stephen Evans, campaigns manager at the National Secular Society, welcomed the move.

"By omitting any explicit mention of God or religion, the Guide association has grasped the opportunity to make itself truly inclusive and relevant to the reality of 21st century Britain," he said.

"The new secular promise can now be meaningful and relevant to all guides and potential leaders, whatever their beliefs – and sends a clear signal that Girlguiding is equally welcoming to all girls."

Andrew Copson, chief executive of the British Humanist Association said: "We wholeheartedly welcome the progressive step that Girlguiding have taken today of making their movement genuinely open to all, including the large number of girls and young women who don't believe in any god.

"We welcome the fact that the new Promise is about personal integrity and ongoing and active self-reflection, both of which sit well alongside a sense of responsibility to others and to the community.

"Unlike its predecessor, this is a Promise that is inclusive of all girls and young women whether religious or non-religious."