Mark 12:30 says to Love God, but rather than stop there, the writer goes on. Instead of just saying "love God", it says to love him with all your passion, prayer, intellegence, and energy. What does this mean? Think about this: when you pray, do you ask for material goods the whole time instead of praising the Creator? Or, do you think bad thoughts about a co-worker or sibling? Maybe you're jealous of Suzy's new handbag. The one you have wanted forever, but can't afford. Then you go to Church on Sunday, sing some songs, and say you love God. But do you?
In order to truly love God, we must devote our whole selves to Him all the time, not just on Sundays at Church, but every day.
Devote all your energy and intelligence and any other gifts God gave you to Him.
Jesus loves you. Love him back.

Mark 12:30