Three farmers each desired a good harvest. One farmer knew that only God can cause a seed to sprout and so did no work himself. At the end of the season he had only a field of weeds. The second was a lazy farmer; rather than labor for his harvest, he drove to the nearest supermarket and bought canned vegetables. The third farmer labored in season and out and with difficulty brought forth a bountiful harvest.
One worshipper knows that only God can cause a heart to fill with delight and so does no work in preparing for worship. At the end of the service he has little more than he started with. The second worshipper is lazy, he sees no reason to prepare for worship and instead uses his money to find delight elsewhere. The third worshipper knows the great worth of worship and prepared himself thoroughly for it, bringing forth a heart brimming with delight.