In the Philippines I heard a local pastor use the following parable to illustrate Christ's offer of rest (Matthew 11:28) and the response of people who won't trust him completely:

The driver of a carabao wagon was on his way to market when he overtook an old man carrying a heavy load. Taking compassion on him, the driver invited the old man to ride in the wagon. Gratefully the old man accepted. After a few minutes, the driver turned to see how the man was doing. To his surprise, he found him still straining under the heavy weight, for he had not taken the burden off his shoulders.