Christians gathered outside Buckingham Palace on Sunday for a service celebrating the 60th anniversary of the Queen's coronation.
The congregation of young and old rolled out a giant scroll with the words "Beloved Queen". Eight members of the congregation wore T-shirts with letters that together spelled "Let's Live the Oath!!".
The T-shirts referred to her coronation oath to "maintain the laws of God" and "the true profession of the Gospel".
The service was held as a gesture of gratitude for the Queen's service over six decades and her faithfulness to the coronation oath.
In his address, Bishop Michael Nazir-Ali thanked the Queen on behalf of Christians and expressed his hope that the Government would not put her in a compromising position.
The service took place on the eve of the debate in the House of Lords on the Marriage (Same Sex Couples) Bill.
Around 2,000 guests will attend a service of thanksgiving for the Queen at Westminster Abbey on Tuesday.
The Queen will be accompanied by members of the royal family at the service. The sermon will be delivered by the Archbishop of Canterbury. David Cameron will give a reading.