heart and soul

Noun

 * 1) the core of a thing; the most essential or important part
 * The heart and soul of any democracy is its electorate.
 * 1) passion; true commitment
 * She put her heart and soul into the project.

Synonyms

 * ; ; See also Thesaurus:gist

Adverb

 * 1) With the utmost earnestness.