The snake?

 

And the Lord said unto Moses, Make thee a fiery serpent, and set it upon a pole: and it shall come to pass, that every one that is bitten, when he looketh upon it, shall live.
And Moses made a serpent of brass, and put it upon a pole, and it came to pass, that if a serpent had bitten any man, when he beheld the serpent of brass, he lived [Num. 21:8–9].
There is a marvelous lesson here, you see. They are to look at the brazen serpent, and they are to look in faith. In fact, they would not look if it were not in faith. I can well imagine some of the folk saying that this was just nonsense. They would want something else, something more tangible than just turning around to look at a serpent of brass. But, of course, if a man would not turn to look at the serpent of brass, he would die.
Now, we don’t have to guess at the meaning of this and the lesson for us. When our Lord was talking to Nicodemus on that dark night, He said, “And as Moses lifted up the serpent in the wilderness, even so must the Son of man be lifted up: That whosoever believeth in him should not perish, but have eternal life. For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life” (John 3:14–16).
How was the Son of man lifted up? You say, on a cross. Yes, but He was dying on the cross of Barabbas, and Barabbas was a thief and a murderer. Barabbas was guilty and was worthy of death. Jesus was not. Our Lord was made sin for us. On that cross, He not only has taken the place of Barabbas but also your place and my place. God permitted this and did this because He loves us. But God cannot save us by His love. It doesn’t say that God so loved the world that He saved the world. Not at all. God so loved the world that He gave His only begotten Son. Now what God asks you to do, my friend, is to look and live. Look to Christ! He is taking your place there. You are a sinner and it is you who deserves to die. Christ did not deserve to die. He died for you.
We read here that this serpent of brass was made, and those who looked to it lived. Those who did not look to it—died. It is just that simple today. Either you are looking to Christ as your Savior because you are a sinner, or you are not doing it. If you are not doing it, I don’t care how many times you have been baptized, how many ceremonies you have been through, how many churches you have joined, or who your father and mother happened to be, you are a lost, hell-doomed sinner. You must look to the Lord Jesus Christ. It is just as simple as that. And by the way, it is just as complicated as that. What a problem people have today. They would rather look to themselves and to their own good works, trusting that somehow their own good works might save them. It is a problem for people to admit they are sinners and to look to Christ and trust Him.
McGee, J. Vernon: Thru the Bible Commentary. electronic ed. Nashville : Thomas Nelson, 1997, c1981, S. 1:ix-507

Response to comment [from a Christian]: "How very interesting. If memory serves me correctly Nicodemus was a pharisee and came to Jesus in the dead of night because he did not want it known that he had sought understanding from Jesus..."

"John treated the idea of secret disciples negatively (see [Jn] 12:42, 43) but since Joseph publicly risked his reputation and even his life in asking for the body of Jesus, John pictured him in a more positive light." MacArthur, John Jr: The MacArthur Study Bible. electronic ed. Nashville : Word Pub., 1997, c1997, S. Jn 19:38

The snake?