The phrase "heartfelt prayers" is correct and usable in written English.
It can be used when expressing sincere condolences or support for someone in distress or mourning.
Example: "During this difficult time, please know that you are in our heartfelt prayers."
Alternatives: "sincere thoughts" or "genuine prayers."
And with the crowd finally hushed, he asked to send "heartfelt prayers to their loved ones".
We offer our heartfelt prayers and deepest sympathy to the DeBellis family for their great loss.
"My family and I are grateful for your many heartfelt prayers and kind thoughts.
Rather than ordering this roomful of Protestants to be burnt at the stake, Ratzinger assured them of his "heartfelt prayers" for all those taking part in this convocation.
Our heartfelt prayers go to the victims and their families, and they will no doubt be remembered in Friday prayers around the world.
"His reaction is the case has always been a tragedy," Mr. London said, "and his heartfelt prayers go out to the Edwards family".
Post a heartfelt prayer for all your Facebook friends who haven't met "the one" yet.
The way to curtail humans' ineradicable potential for evil is not soaring rhetoric or heartfelt prayer, but effective laws that govern the interaction of citizens in society.
Faced with the American school system's lengthy summer hiatus, harried parents must regard sleep-away camp as the answer to a heartfelt prayer.
The good and bad suffer alike, although a heartfelt prayer to God can bring about miracles such as the restoration of severed hands and feet, or transformation from beast to human.
As it dawned in the early hours of November 5 that Barack Obama would be the next president of the United States, there will have been few citizens celebrating harder, or silently saying a more heartfelt prayer of thanksgiving, than the multi-million-selling R&B singer, producer, songwriter and label-owner Akon.
