"When the angels went away from them into heaven, the shepherds said to one another, "'Let us go over to Bethlehem and see this thing that has happened, which the Lord has made known to us'. And they went with haste..."
Anybody work in an office where you have a holiday party... for Veteran's Day? MLK Day? Groundhog Day? Do you happen to live in a part of the world where you and almost everyone you know goes shopping for Armed Forces Day? Ever see the shopping malls filled up for Tax Day? Valentine's Day and Halloween are pretty big commercial holidays but I don't know of any workplaces that shutdown and pay workers to stay home for those days.
Everybody has more than enough to do and even more options during the Christmas season. Whether one celebrates the specifically Christian roots of the holiday or not, it is generally expected that the season brings with it interruptions and worthwhile investments of time and money. Even as many are fearful of the growing trend of secularization in the West, there are few who would espouse the old objections of Ebenezer Scrooge, "Christmas time--a poor excuse for picking a man's pocket!" Scrooge wasn't in favor of giving Bob Cratchit the day off, but even he, miserly as he was did that much, albeit fictitiously. People seem to make time for what they either desire to do or to do what is apparently expected of them.
Consider the shepherds' response to the "angelic invitation". First of all, one could hardly call it an invitation in our modern sense seeing there was no explicit request for their presence. Telling shepherds what to expect or how to verify the birth of a promised savior required them to leave their fields and go to Bethlehem. See how the RSVP was missing? See how the phrase "you are cordially invited" was severely lacking? Not even something like, "Your presence is requested" was used. This was no invitation, it was virtually a summons. They were willing to leave their job, even while on duty, to obey a higher calling and a more urgent need.
Naturally, if we were to see a man at our door with chicken scratchings on a strip of paper we might wonder what he was doing there since we did not invite him. As he goes on and on about a particular office building and room number, we may well be very distracted at his untimely appearance and be distant in our thoughts looking for ways to dismiss him. However, if he has a shiny badge, a gun in his holster, and a couple cop cars behind him, we are likely to deduce his visit is not a pleasantry but official business of government. Failure to distinguish between the two would bring more problems than the undesired visiting we're mandated to do.
The angels in this passage came from a celestial court with a message from the King of the Universe. As powerful as they were, their message was even more weighty because it carried the importance of God behind it. Amazing how presumably unschooled, illiterate shepherds had enough sense to understand that. And it would be even more amazing--if it wasn't so pitiful--that Christians today, with the same obligation to tell the world of God's salvation in Christ, think sharing the summons that is the gospel is optional.