We're not delivering our mail but God's

I just heard Mark Dever give a really good illustration of what being a pastor is about.
He was saying that you expect the mail man (postman - UK) to deliver your mail, you entrust him with your message and you expect him to mail it, not to write his own letters. Similarly,

"Its not our own mail we're delivering, Its God's mail for his people ...
its not whatever we want to talk about ...
he's given us the message of his word, and he asks us to deliver that to his people."

You can watch the message here:

http://www.ligonier.org/rym.php