with all (one's) heart
With one's sincerest feelings. I will love you with all my heart until the day we die. I just wanted to tell you, with all my heart, how proud I am of you.
with all one's heart (and soul)
Cliché very sincerely. Oh, Bill, I love you with all my heart and soul, and I always will! She thanked us with all her heart and soul for the gift.
with all (one's) heart
1. With great willingness or pleasure.
2. With the deepest feeling or devotion.