have (one's) heart in (something)

To be emotionally and enthusiastically involved in something; to do or undertake something with passion and zeal. My mom really has her heart in her new business. By all rights, our team should have won the game, but I guess they just didn't have their hearts in it. A: "You don't have your heart in baking Christmas cookies this year, do you?" B: "No. It's just not the same without Grandma."

have (or put) your heart in

be (or become) keenly involved in or committed to an enterprise.