Dear xxx,
I learned with sadness of the death of yyy, and I wanted, beyond the very sincere condolences that I present to you, to assure you of my friendship and my support in these difficult moments.
[Believer Mode]
I’m sure that God, in His infinite goodness, will know how to welcome it… etc etc, I’m not a believer, we’ll have to manage with that.
I am thinking of you in these moments, and once again express to you my deep sadness for this disappearance that affects you.
Etc etc, it’s a first draft, and I’m not used to this kind of thing… if it can give you ideas…