"And the Lord spake unto Moses, saying, Speak unto the children of Israel, that they bring me an offering: of every man that giveth it willingly with his heart ye shall take my offering."
"Every man according as he apurposeth in his heart, so let him give; not bgrudgingly, or of necessity: for God loveth a ccheerful dgiver"
2 Corinthians 9:7
When we talk about a willing heart, we are basically talking about "want to." If there is something we want to do strongly enough, somehow we will find a way to do it. With it we can lose weight, keep our house clean, save money, get out of debt, or reach any other goal in life we may have set for ourselves. Our victory or defeat has a lot to do with our "want to."
We are really good at laying the blame for our failures on the adversary, other people, the past, and on and on. But the truth is that most of the time the bottom line is we just don't have enough of the right kind of "want to."
Heavenly Father examines our heart attitude, and whatever we do for Him must be done willingly. God delights in those who give to Him willingly, joyfully, and cheerfully, but not those who give legalistically or under compulsion. I don't believe we receive any reward for doing things with a bad attitude.
The passage in 2 Corinthians is easy for me to relate to. When Allisa is helping around the house she does so with a huge smile and a great heart attitude. She is a pleasure to be around. She is always asking how she can help; if anyone would like something to eat or drink; she asks to walk the dogs and other acts of service and kindness. She does everything willingly and without being compelled.
When I have had opportunity to teach in Relief Society or Sunday School I expressed the different heart attitudes that exist when we pay our tithing; when we accept callings; when we attend church; or when we participate in Service or Humanitarian Projects. Do we do these things because we feel obligated; or it's a commandment; or because it is expected of us - or do we do them because we are grateful and we love to serve; or because we feel that it is a priviledge.
Remember, Heavenly Father loves a cheerful willing Son or Daughter.