This autumn saw the end of one era in the UK, and the beginning of another with the changing of the monarch for the first time in most of our lifetimes.

In just a few short weeks, all eyes will be on the new King as he takes up the mantle of his mother's annual, and very personal, address to the nation: the Christmas speech. Many Christians, who have been heartened by how the Queen used the speech to share her faith, are curious to see what this significant speech will contain, and the glimpses it will give into the King's leadership during this new Carolean era.

The nation King Charles will speak to this Christmas is worlds apart from the one his mother inherited. The latest UK census has shown that the number of people identifying as 'Christian' has further decreased compared to 2011, with less than half of the population of England and Wales describing themselves as Christians. Similarly, the religious diversity for the other 14 Commonwealth nations of which King Charles is head of state is continuing to shift.

With King Charles also head of the Church of England, this picture leads us to some – at least at first glance – paradoxical questions. How can he be both 'Defender of The Faith' and 'protector of the faiths?' And more importantly, what aspects of kingly leadership will he need to exhibit to walk this fine line?

Emulating Jesus - and the Queen

In his inaugural address, King Charles spoke of the need to remember and draw strength from the light of his mother's example, a life of humble, obedient service to the nation and the Commonwealth spanning over 70 years. But it was also a life of sincere faith, a life which Queen Elizabeth ensured that King Charles grew up deeply rooted in.

Like Jesus, Prince Charles was brought up knowing exactly what his God-given purpose was: to be a king and to serve people with loyalty, respect, and love throughout his life, whatever their background or beliefs.

A Biblical foundation

I heard a talk aimed at pastors recently that I both agreed and disagreed with simultaneously. The preacher said that sermons needed to be three things: political, socially actionable, and informative, telling listeners something new. But they somehow missed the fact that above all else, sermons need to be Biblical.

King Charles will undoubtedly face significant pressure in his time as monarch to weigh into political grey areas, such as the potential break-up of the UK or partial dissolution of the Commonwealth. But if he remains above party politics and commits himself to living out the standards set in the Bible, for example caring for the poor and the environment, then he should not be afraid to use his voice.

Huge challenges also await in maintaining and improving international relations. The UK's colonial history will do King Charles no favours and he will need to communicate to the Commonwealth in a way that does not come across as imperial, but rather recognises and even appreciates their independence. Instead of the 'West is best' attitude that many of these nations have become historically accustomed to, sharing our learnings to help them avoid the mistakes that the UK has made will go a long way to building rapport with our overseas neighbours.

This is one of the founding beliefs at Langham Partnership, which was set up by John Stott to walk alongside the global church in Biblically equipping leaders to help multiply disciples in majority world nations.

Kingly leadership means living out Biblical leadership. As King, Charles will do well as he defends faith and nations by looking to the Queen's example, Jesus' ministry, and the Bible. It's important we remember that the Bible is not just a book full of stories, but a living, breathing manual that we should draw on for strength, comfort, purpose and guidance.

How will he come across in this year's Christmas speech, I wonder?

Simon Foulds works for Langham Partnership as Supporter Development Manager. He has worked in the charity sector for over 30 years, holding fundraising roles for The Children's Society, Treetops Hospice, Bible Society, Royal British Legion and The National Holocaust Centre. He lives in Nottingham and is a local preacher for the Methodist Church in the Nottingham South Circuit.