Greetings Vic and fellow forum members. I too know that there are many verses that are pulled out of Scripture context at times and use for various purposes which are often not the exact purpose of the writer who originally wrote the scriptures. In this particular passage and chapter we have words attributed to Christ Himself written down for those of us to follow to hear and read.
While there are many who do not believe scripture is God's word at all there are also those that differ in interpretation and while some Scriptures I believe God can use in varying ways depending on what He wants to Impart unto specific Christians through His Holy Spirit other sections are seemingly plain and not as much open to interpretations. It is also no secret that various denominations are whom they are based upon their own beliefs and opinions as to Scripture and how it correlates with the Churches teachings. That said I would like to insert just a few of my own personal beliefs/opinions about the Scripture passage for CONSIDERATION and discussion.
While I do, personally, see divisions of thought within this Chapter I also see a common theme and that is of Salvation for Mankind. The first section of this chapter I see as verses 1-21 and contains several thoughts within that section. First the dialog between Christ and Nicodemus reveals for us not only the need for Salvation but the source of mankind's Salvation. It is also the revelation of two areas of life or two dimensions, one fleshly and of this world and the other Spiritual and of the Spiritual afterlife, after the Physical life ceases.
vs 3 I see as Christ expression that Salvation is essential/necessary for mankind to satisfy God and experience the afterlife in God's presence/Heaven.
vs 5-6 is where the distinction of mankind's earthly physical existence (the body) is contrasted with mankind's unique creation of our spirit/soul entity. Christ here reveals that there are things that belong to the physical world/nature and that mankind has a spirit/soul that is of the Spiritual realm just as God exist within the Spiritual Realm apart from the Physical.
vs 10 is where Christ acknowledges that Nicodemus was knowledgeable in the Old Testament or Scriptures up to that time. That from those same writings he should have been able to realize who Christ was and why he was there but that knowledge wasn't sufficient for Salvation.
vs 12 I see as Christ simply saying that the things that should be simple and evident from the scriptures he has, teaches and knows yet they are seemingly difficult to conceive so why should he expect to be able to comprehend the infinitely greater and much more complicated things of God and that has to do with Heaven that are not evident from Scripture, at least at that point in time?
vs 13, 14, & 15 Christ explains to Nicodemus just what is the path to Salvation and eternity with God in Heaven, Spiritual Salvation for mankind that is. Christ, God come to earth in man's flesh, has to be Crucified, Sacrificed and mankind accept and believe on that Sacrifice of Christ on the Cross in the same way that people obtained physical salvation/healing from the judgment from the snake bites looking on Moses as he held up the serpent for healing only where with Moses it was physical healing with Christ it was Spiritual healing of Salvation from our sins and sinful nature. In one case it was Salvation from Physical death the latter (Christ) from Spiritual death.
vs 16 essentially the reason God allowed Salvation for man and the Method by which it came. Reason was unmerited LOVE and the method was God's son or effectively God's Spirit/God in Human Flesh dwelling among earthly Mankind.
vs 17 The reason Christ came, this time, was to bring Salvation and not Judgment or Condemnation of Mankind. Now is not the Judgment of mankind but the offer of Salvation of clemency, of Justification.
I have separated vs 18 because here while I agree with you I believe I differ on one aspect. Where I do very much believe in predestination I do not agree that it applies to mankind in that certain of us are predetermined to be saved while others are not. I do very much believe that whosoever means whoever believes and accepts God's offer of Salvation. What I do believe was predestined long ago was the process by which Salvation would be obtained. I believe that Christ is telling us that at some point in time past God pre-determined that there would be judgment upon Sin, mankind's sin and the sins of angels and others. But also pre-determined would be the way of escape and the way of Justification and forgiveness from the verdict/Judgment upon sin and that also includes the process by which that Justification was to come. God pre-determined that He, through Christ, would offer the only acceptable perfect blood sacrifice to atone for mankind's sins against Him. Pre-determined that whoever looked to Christ, looked upon Christ, as their Savior and Sacrifice could find Salvation from Spiritual Death, the penalty upon Sin that was set forth long ago. Also revealed within verse 18 was the fact that the penalty or judgement upon Sin was there before mankind and that mankind is and was condemned all along and that the penalty and judgment upon sin rest on mankind's head from birth and only those who accept Christ Sacrifice remove themselves from that verdict by taking Christ shed blood as their Sacrifice for their sins. For those that do not accept that or look upon Christ then nothing else is there that can take away that verdict that resides upon them for they already stand condemned awaiting Judgment. Until that Judgment or the moment when they are no longer able to make that decision with their mental ability (physical death) then they can choose to accept the only provided sacrifice for mankind's sins (Jesus Christ).
vs 19-21 simply contrast light and darkness ... knowledge to ignorance and being Saved to not being Saved. The evil nature of mankind is revealed and acknowledged that it is abhorrent to God's nature by it's own virtue and being. It is a question of where your priorities are and revelation that there is a way of escape available but that mankind has a choice and a decision to make and the ability to make that decision in and of themselves. And lastly that for those who have made that decision to accept Christ that their Salvation is not of themselves nor anything they have done by act or deed but rather by God's provision. Our Salvation is of and by God's own merit and Goodness and out of His own Love.
Again regarding predestination I believe it is the way of Salvation that was predetermined and not the specific individuals that would obtain salvation.
Ephesians 1:5 (ESV)
5 he predestined us for adoption as sons through Jesus Christ, according to the purpose of his will,
Ephesians 1:11 (ESV)
11 In him we have obtained an inheritance, having been predestined according to the purpose of him who works all things according to the counsel of his will,
Ephesians 2:10 (ESV)
10 For we are his workmanship, created in Christ Jesus for good works, which God prepared beforehand, that we should walk in them.
&
Romans 8:28-30 (ESV)
28 And we know that for those who love God all things work together for good, for those who are called according to his purpose.
29 For those whom he foreknew he also predestined to be conformed to the image of his Son, in order that he might be the firstborn among many brothers.
30 And those whom he predestined he also called, and those whom he called he also justified, and those whom he justified he also glorified.
Romans 10:12-13 (NIV)
12 For there is no difference between Jew and Gentile--the same Lord is Lord of all and richly blesses all who call on him,
13 for, "Everyone who calls on the name of the Lord will be saved."
I also believe that God Calls people and enables them for Salvation. For those that seek God I do believe that God will enable them, call them, via His Holy Spirit and that a person must be Spiritually enabled to understand their Spiritual needs and the available sacrifice that is there for them and at that moment God convicts/calls them for their decision. I do not believe that mankind can just be guaranteed that the call will come when they so desire it. That a person can wait until their last breath and be guaranteed that God will respond with a call when they desire it so I believe it is very important for mankind to respond when God Calls and Spiritually enables them by His Holy Spirit. That is my personal belief and I could be wrong but I believe scripture backs up that belief.
John 6:63-65 (NIV)
63 The Spirit gives life; the flesh counts for nothing. The words I have spoken to you are spirit and they are life.
64 Yet there are some of you who do not believe." For Jesus had known from the beginning which of them did not believe and who would betray him.
65 He went on to say, "This is why I told you that no one can come to me unless the Father has enabled him."
John 6:37 (NLT)
37 However,those the Father has given me will come to me, and I will never reject them.
Now I also believe that there are specific individuals also that are predestined by God for a specific purpose and called by Him for a specific purpose. John the Baptist being one of those persons. As for others I am not confident in changing my opinion regarding Salvation in general for I do believe that the Bible and Scripture is consistent throughout it's whole and therefore to discover the meaning of a dis****ble topic we can look for answers and clarification in other books and from other writers or dialog of those who were there and sat under Christ teaching. I will admit though that there are scriptures that can be used for both opinions and views but I deeply feel and believe that Salvation is open to all, to whosoever but that it is so critical and precious that when presented to a non-believer and non-saved person that they should be so very careful to consider the opportunity given and presented unto them and not reject the time that God enables or calls them.
I specifically liked the statement that I believe Dwight Moody said regarding Predestination and Salvation. It went something like this, but not exact "Preach the Gospel to everyone and if by some miracle you happen to save someone who was not elect then I'm sure God will forgive me". Essentially it is not my place to judge/determine who is and who is not capable of being saved.
That's how I interpret and see John Chapter 3 and the context of Salvation. I'm sure that differs from some but that is the way I see it and why i believe it is that way.