As Moses lifted up the serpent in the wilderness, even so must the Son of Man be lifted up,
The usual analogies drawn from the brass snake are these: (1) in each case, those who were benefited could not have been aided any other way; (2) the lifting up in each case was before all Israel, the serpent in the camp, Jesus on the cross; (3) the design in each case was to save life, the serpent physical, the Lord eternal life; (4) the manner of the cure is similar, the Israelites having merely to look on the serpent in order to be cured, and Christians, of course, having to do nothing except believe in order to be saved!  Such analogies are not merely untrustworthy; they are fallacious and contradictory to the Sacred Scriptures.  There are far more dissimilarities than there are similarities, thus: (1) the brass serpent was of different material from the deadly snakes that were tormenting Israel; but Jesus was made in all points like unto his brethren  (Hebrews 2:17); (2) Israel was forbidden to worship the brass snake; but all people are commanded to worship Christ; (3) the brass snake eventually became an idol and was defiled and burned up (2 Kings 18:1,4); (the manner of appropriating the blessing is exceedingly diverse in each case, there having been no moral or spiritual conditions whatever in the healing of snake bites, not even faith).  Now, when the Pharisees looked upon Jesus on the cross, were they saved?  No!  Far more than looking is required for salvation in Christ, as revealed in the next verse.  And, as for those who would take this verse as the basis for promising salvation to all who "look upon" Jesus, and then interpret that to mean "faith only," it should be pointed out that Jesus had just revealed to Nicodemus that absolutely nothing short of being born again, born of water and of the Spirit, could suffice for entry into God's kingdom.