The Princess of Wales said Christmas is one of her "favourite times of the year" as she shared the "greatest gift" we can all receive.
Kate has penned a heartfelt letter, which will be given to all of the guests who are invited to her Christmas carol service at Westminster Abbey next week.
In her message, Kate says the festive season is a "time for celebration and joy" but also "gives us the opportunity to slow down and reflect on the deeper things that connect us all".
She added: "It is when we stop and take ourselves away from the pressures of daily life, that we find the space to live our lives with an open heart, with love, kindness and forgiveness - so much of what the Christmas spirit is all about."
Kate, who has a difficult year after undergoing major abdominal surgery and being diagnosed with cancer, described "love" as the "greatest gift we can receive".
"Not just at Christmas, but every day of our lives. Love is the light that can shine bright, even in our darkest times. We all have something we can offer one another. Gentle words or a receptive ear, an arm around an exhausted shoulder, or silently being by someone's side."
It echoes the sentiment of the Princess' video message released back in September as she announced she had completed chemotherapy, where she said her experience "reminded William and me to reflect and be grateful for the simple yet important things in life, which so many of us often take for granted. Of simply loving and being loved."
Kate will be surrounded by family and friends at the service on Friday 6 December, which is likely to include her children, her parents and siblings and members of the royal family.
She ended her message by writing: "This Carol Service is a heartfelt celebration of every one of you, and a reminder that at Christmas, and throughout the year, we must all shine for each other. Because in times of joy and sadness, we are all each other's light."
Kensington Palace has previously shared how the Princess wanted the service to "reflect upon the importance of love and empathy, and how much we need each other, especially in the most difficult times of our lives. The service will shine a light on individuals from all over the UK who have shown love, kindness and empathy towards others in their communities".
The Prince of Wales will be among the guests to deliver readings at the event, alongside Olympian Adam Peaty OBE, Sophie Okonedo CBE, Michelle Dockery and Richard E. Grant.
Candles will also be lit by Lindsey Burrow (wife of the late rugby star, Rob Burrow), cyclist Sir Chris Hoy MBE, and teammate Paralympians Lizzi Jordan and Danni Khan.
A 1,600-strong congregation will get to watch performances by Olivia Dean, Gregory Porter, Paloma Faith, JP Cooper alongside the Westminster Abbey Choir.
The church will be decked out with sustainable, festive decorations and foliage, and in another touching gesture, guests will be able to dedicate a decoration to someone who has supported them throughout their life and place it on the 'Kindness Tree' outside the Abbey.
In addition to the service in London, 15 community carol services will be taking place around the UK throughout December.
Royal fans will be able to watch the concert as part of Royal Carols: Together At Christmas, a special programme, airing on ITV1 and ITVX on Christmas Eve.