"We get a surprising glimpse of what service to God means for Jesus in Matthew 6:24. He said, 'No one can serve two maters, for either he will hate the one and love the other, or he will be devoted to the one and despise the other. You cannot serve God and money.' The surprising thing here is that serving God is compared to serving money. But how do you serve money? Not by helping money or meeting money's needs. You serve money by treasuring it so much that you shape your whole life to benefit from what money can do for you.
So it is with God in the way Jesus sees the service of worship. We do not help God or meet God's needs ('The Son of Man came not to be served,' Mark 10:45) Rather we serve God by treasuring him so much that we shape our whole life so as to benefit from what he can do for us. And, unlike money, what God can do for us about all other treasures is be for us everything we have ever longed for."
(excerp from "What Jesus Demands from the World" by John Piper.)