Repeatedly, the Bible says to "serve the Lord with all your heart." God wants you to serve him passionately, not dutifully. People rarely excel at tasks they don't enjoy doing or feel passionate about. God wants you to use your natural interests to serve him and others.
How do you know when you're serving God from your heart?
The first telltale sign is enthusiasm. When you're doing what you love to do, no one has to motivate you, or challenge you, or check up on you. You do it for the sheer enjoyment. You don't need rewards, or applause, or to be paid, because you love serving in this way.
The opposite is also true: When you don't have a heart for what you're doing, you're easily discouraged.
One characteristic of serving God from your heart is effectiveness: whenever you do what God wired you to love to do, you get good at it. Passion drives perfection. If you don't care about a task, it is unlikely that you'll excel at it.
On the other hand, the highest achievers in any field are those who do it because of passion, not duty or profit.
We've all heard people say, "I took a job I hate in order to make a lot of money, so someday I can quit and do what I love to do." That's a big mistake. Don't waste your life in a job that doesn't express your heart.
Remember, the greatest things in life are not things. Meaning is far more important than money. The richest man in the world once said, "A simple life in the fear-of-God is better than a rich life with a ton of headaches" (Proverbs 15:16 MSG).
Don't settle for achieving "the good life," because the good life is not good enough. Ultimately, it doesn't satisfy. You can have a lot to live on, and still have nothing to live for. Aim instead for "the better life" - serving God in a way that expresses your heart.
Figure out what you love to do - that which God gave you a heart for - and then do it for his glory!