hate it when I hit the wrong button!

anyway- in the above verse you could even change "Saviour" to "Child" without offending any but the most rabid Christians, yet lessen the overall "Christian" flavour - for those who do not care to see the (in my opinion) quite obvious Nativity story.

then finish with:

Then with delight they took their flight, and wing'd their way to glory,
The shepherds gazed and were amazed, to hear the pleasing story;
To Bethlehem they quickly came, the glorious news to carry,
And in the stall they found them all, Joseph, the Babe, and Mary.

That gives you four verses - and you pretty well remembered only three - so should be both long enough and complete enough to hang together as a song and a story.