The partner is described here as the best gift ever given by life to the author of the letter.
Dear.....
Today is the day of love and that's why I thought I would give you a very special gift: a love letter. I want to thank you for everything you have done for me so far. You have shown me that you love me too.
In our time together we went through ups and downs, but it was always clear to me that you are the great love of my life, to whom I want to be faithful until the end of my days. Even if problematic times should come our way, you can always rely on me.
On Valentine's Day, I always realize that without you, I was in fact lonely and how much I wanted such a wonderful person like you by my side. You are the best gift life has ever given me and for that I am grateful every day.
I love you so much that I can hardly express it in words and wish that we spend many more Valentine's Days together.
With love