It is the practice of the Scottish denominations which hold to the establishment principle to send a letter from their highest court (whether General Assembly or Synod) to Her Majesty the Queen. In it, the Assembly will mention important events in the life of the Monarch, the nation, and the church. This might be thought of as being an antiquated if not anachronistic practice. However, it has continuing importance.
Today the Queen’s duties as head of state are mostly ceremonial. But ceremony has meaning; and these letters have meaning in that context. She rules over a constitutional monarchy; and these letters have meaning in that context too.
Firstly, Christians are to honour and pray for their civil rulers. These letters are expressions of that honour and an assurance to the titular head of state that prayer is being made. In praying for the head of state as such, the whole apparatus of government is included in the petition. This holds true for all commonwealth countries. In the United States, an equivalent might be to pray for all those who have sworn to uphold the Constitution.
Secondly, the United Kingdom is constitutionally speaking a Christian country which tolerates the practice of other religions. The sending of these letters supports that constitution. In the United States, the strength of the connection between Christianity and the Constitution is a debated subject. Nevertheless, Christianity contributed many ingredients to the melting pot of ideas out of which it came; and that should not be forgotten by whomever is in power.
Thirdly, both the church and the Monarchy should be above party politics. This allows the conceit of distinguishing the Sovereign from the elected representatives who advise her. One might remonstrate with the advisors without resisting the power. It is more difficult to separate the idea of the Presidency from the incumbent President.
Lastly, the letters are a reminder of the ordinary, of the norm. So much time, effort, and ink (real and virtual) have been spent in recent years on the extraordinary. At first, it was to re-examine the rationale for the wars, civil and revolutionary, which shaped the United Kingdom and the United States. Now, discussion of the exception has overtaken teaching on living by the rule.
It is counterintuitive to think that a woman living in a gilded palace has a better grasp of the common good, a surer finger on the public pulse, than the elected representatives who inhabit the debating chambers of democracy. But she does; because when she reads a letter from a General Assembly, she sees a denomination of Christian people whose ordinary lives of salt and light bring stability to society, not a block of voters to be favoured or offended depending on the latest opinion poll. Under other constitutions, who reminds the politicians of the people whom they take for granted?