Because He was also lifted up.
I understand that you need to defend your tradition. But if you take the passage at face value, it shows regeneration preceding faith.
You say that people need to be regenerated in order to "understand" the gospel.
So here is what is happening in John 3 ...
(Jn. 3:3) Jesus tells Nicodemus he must be born again, BUT
(Jn. 3:4) Nicodemus DOESN'T understand.
(Jn. 3:5,6,7,8) Jesus says, marvel not.
(Jo. 3:9) Nicodemus STILL doesn't understand.
Now if regeneration precedes faith, (because it allows people to understand), Nicodemus is obviously NOT regenerated.
(Jn. 3:11, 12) Jesus QUESTIONS why Nicodemus doesn't understand.
Observe:
3:12 If I have told you earthly things, and ye believe not, how shall ye believe, if I tell you of heavenly things? John
If regeneration PRECEDES faith, why doesn't Jesus seem to be aware of that?
Jesus is God, who works in harmony with the HS. Jesus is talking to Nicodemus about being born again, but it seems the HS isn't co-operating, because clearly, Nicodemus has no idea a out what Jesus is talking about.
Now Jesus actually asks Jesus, "If I have told you earthly things, and ye believe not, how shall ye believe, if I tell you of heavenly things?"
Now think about that question.
Part one:
"If I have told you earthly things, and ye believe not"
Jesus gives His question to Nicodemus a preface ...
I've told you earthly things, and ye believe not".
The word "you" and "ye" are plural. Jesus has been teaching while Nicodemus has been with others (rabbi's); and none of them believe what He has been saying, even though, He has taught about earthly things.
Part two:
"how shall ye believe, if I tell you of heavenly things?"
Jesus point blank asks Nicodemus, How then can you expect to believe heavenly (spiritual) things?
It is very clear that although Jesus may have been telling Nicodemus ABOUT being born again ... Nicodemus HASN'T been born again.
From this point, Jesus begins to tell Nicodemus why He came down from heaven.
Question ... Why does Jesus ask Nicodemus the previous question?