Every commentator on this lectionary selection from Numbers 21 calls it either bizarre, strange, weird, peculiar or the like. Just reading the account makes you scratch your head. Why the lectionary selection committee decided to include it - from all the rest of scripture it could have chosen - is equally strange. In any case, here it is.
Moses has been leading God's ornery, complaining, griping people for decades now. They're almost at the end of the journey. But the muttering starts again. They don't like the food; they don't like the water; they don't like anything.
God seems to snap. God has had it with these people. As if thinking that these people need something to really complain about, God sends swarms of poisonous snakes on them, depicted above by Agnolo Bronzino's The Adoration of the Bronze Snake. (Look closely; you'll see snakes everywhere. Ew!)
The people are getting bitten and dying. They plead with Moses to intercede, admitting that they crossed a line in their complaining. Moses prays and God answers by telling him to construct a snake image and set it on a pole. When the people get bitten, they should look at the snake-on-a-stick and be healed. Moses manages to make one from bronze, and it works.
What was that all about? You better consult the sermon video.
Jesus' conversation with Nicodemus in John 3 has not been going well. Nicodemus doesn't seem to be getting it at all. Jesus seems to be reminded of Numbers 21, how the snake-on-a-stick is like the Son of God in vs. 14, and Nicodemus is as clueless as the people of God in the wilderness.
Check out the sermon video below and see how John 3:16 reveals Jesus as the snake-on-a-stick!