An Edinburgh minister with a passion for Scripture Union has been installed as the Church of Scotland's new Moderator. 

The Rt Rev Colin Sinclair was installed on the first day of the Church of Scotland's General Assembly on Saturday. 

Addressing the Assembly, he called his new role a "singular honour". 

"For your grace, love, and forgiveness when I get it wrong, I thank all of you who have invested time into my life and my ministry," he said.

"It all started with a Scripture Union holiday, I little knew then how the story of Jesus and his life, death and resurrection would get under my skin and never get out.

"I thank you to all who nurtured me in this faith.

"I had no idea when Jesus said 'Follow Me' all those years ago, how exciting the adventure would be.

"How it would take me around the world. And I thank You again - I pray I am worthy of the trust You have shown to me."

The Edinburgh-based minister takes over as Moderator of the General Assembly from the Very Rev Susan Brown. Mr Sinclair and Mrs Brown are old acquaintances, having first met as students at New College.

"All throughout your years your commitment to the Scripture Union has continued, alongside all the other positions you have taken on," she said in an address to the Assembly.

"You care passionately about communicating the Good News of Jesus Christ to all ages and all parts of the world. You like to see the impact Christ makes to all people.

"This year, you will be asked to say much but I encourage you to listen, too, because you will hear so much.

"My prayers are with You as you follow our Lord on this next stage of your journey with Him."

First Minister Nicola Sturgeon was also in attendance on the opening day of the Assembly along with Scotland's Lord Provosts.

One of Mr Sinclair's two personal chaplains for the year is his son, Rev Tim Sinclair, who was ordained in February and is now serving as the minister of Partick Trinity Church of Scotland.

"It was humbling to be asked to serve as the very junior chaplain to the Moderator," Tim said.

"I have little prior experience of the General Assembly and limited insight into the workings of the courts and councils of the Church. That said, I have known the Moderator for my entire life and perhaps that counts for something.

"At home or in the church, wherever he finds himself, my dad is an energetic and cheerful presence, always willing to throw himself into a challenge.

"He has a rare capacity to take his faith, family and ministry seriously, without taking himself too seriously in the process.

"I look forward to seeing him serve as Moderator and have no doubt that his servant heart, prodigious work ethic, and warm humour will be a blessing to many."

Rev Sinclair is the minister for Palmerston Place Church in Edinburgh, but has a long history with the Scripture Union having attended their summer camps as a high school student before becoming a volunteer in his university days. 

In an unusual side-step from his many Christian commitments, he once took a holiday job as a film extra playing a soldier in the 1975 comedy, Monty Python and the Holy Grail.

After graduating, he went to Zambia with Scripture Union as a training officer in an exchange that would allow two Zambian students to study in the UK.

He later served as the General Director of Scripture Union for eight years and chaired the Spring Harvest Council for seven years. 

Together with his wife, Ruth, he ran a Scripture Union holiday camp for teens at Alltnacriche near Aviemore, in the Scottish Highlands, for 27 years.

In 2004, he took on the role of International Chair of Scripture Union, working with 130 SU movements around the world.

Speaking last year when his appointment as Moderator was first announced, he said: "What I love about Scripture Union is the opportunity to pass onto the next generation faith and the Bible and get them out serving in a world in need."

John Scott, the Duke of Buccleuch and Queensberry, who was representing the Queen as Lord High Commissioner to the Assembly, wished Rev Sinclair a "richly rewarding year in office" in his address.

"Unlike your predecessor you have not had to travel far but for a year you will now be transported into a different world," he said.

"That you have the most wonderful family, all committed to the church, to support you, that there are legions of friends and colleagues here and across many lands, gained through the Scripture Union is testament to your powers of loving leadership and inspiration.

"You are fitted indeed for this highest honour in the gift of your colleagues."