The Queen has praised the "Commonwealth connection" that allows people from different nations to bond and celebrate "diversity", in her Commonwealth Day message.
London will soon host a gathering of leaders from the "family of nations" and the Queen also paid tribute to the biennial event, an example of how consensus can "help to create a future that is fairer, more secure, more prosperous and sustainable".
The Queen's message to the 53 Commonwealth member nations will feature in a service, staged at Westminster Abbey on Monday to mark Commonwealth Day, and attended by the Prime Minister, senior members of the royal family and Meghan Markle - her first official event with the Queen.
The service will be a public acknowledgement by the monarch of the US actress who will soon be joining her family when she marries Prince Harry on May 19.
In her message which follows the theme of this year's Commonwealth Day service - Towards A Common Future - the Queen says: "Through exchanging ideas, and seeing life from other perspectives, we grow in understanding and work more collaboratively towards a common future.
"There is a very special value in the insights we gain through the Commonwealth connection; shared inheritances help us overcome difference so that diversity is a cause for celebration rather than division.
"We shall see this in action at the Commonwealth Heads of Government Meeting which takes place in the United Kingdom next month, bringing together young people, business and civil society from across the Commonwealth.
"These gatherings are themselves fine examples of how consensus and commitment can help to create a future that is fairer, more secure, more prosperous and sustainable."
The Commonwealth has played an important role throughout the monarch's reign, and she takes a special interest in the family of nations.
Harry and Meghan signalled their commitment to the Commonwealth and its people when they both mentioned the institution - which has the Queen as its head - during an interview to mark their engagement.
The prince said they looked forward to travelling around the Commonwealth, meeting some of the 2.4 billion people from the 53 member states.
The Commonwealth Games also featured in the message and the Queen highlighted the vital work of the event's helpers, saying: "Voluntary effort, by people working as individuals, in groups or through larger associations, is so often what shapes the Commonwealth and all our communities.
"By pledging to serve the common good in new ways, we can ensure that the Commonwealth continues to grow in scope and stature, to have an even greater impact on people's lives, today, and for future generations."
Former One Direction band member Liam Payne will perform during the Abbey service and the reflection will give by Dr Andrew Bastawrous, an eye surgeon who has turned a smartphone into an examination tool to combat avoidable blindness in developing counties.
The Duke of Cambridge faced criticism last year when he missed the service to attend his controversial lads-only skiing holiday in Verbier.
Newspapers poked fun at the future king's "dad dancing" when video footage emerged of his antics on the dance floor and in the DJ booth during the trip.
Organised by the Royal Commonwealth Society, the Commonwealth service is the largest annual inter-faith gathering in the UK and will be broadcast live by the BBC.
Other royal guests include the Duchess of Cambridge, Duke of York, Princess Royal, Countess of Wessex, the Duchess of Gloucester and Princess Alexandra.
Also among the 2,000-strong congregation will be the Prime Minister of Malta Joseph Muscat, Commonwealth Secretary-General Baroness Scotland, high commissioners, ambassadors, senior politicians from across the UK and Commonwealth, faith leaders and more than 800 schoolchildren and young people.
After the service, William, Kate, Harry and Meghan will attend a private reception for people involved in the event.