A man's will is determined by their nature within them that influences their choices, but you have man's will determining if they receive a new nature when scripture clearly states becoming born again is determined by Gods will, "Which were born, not of blood, nor of the will of the flesh, nor of the will of man, but of God." (John 1:13).
Is it convenient to forget about verses 11 and 12
Joh 1:11 He came unto his own, and his own received him not.
--Israel rejected him without the Spirit.
Joh 1:12 But as many as received him, to them gave he power to become the sons of God, even to them that believe on his name:
--Man does not need the Spirit to force him to be saved. In this you are wrong.
Verse 13 simply shows the process in which a person is saved. It does not mean that a person must have his heart opened by the Spirit in order to be saved. You are wrong here.
One cannot will their physical birth into this world, likewise one cannot will their spiritual birth, rather in both instances the Father is responsible for both. What influences the will to choose as it does, circumstances in a person's life, God, their spiritual nature, or something else, if something else what?
One is born physically and one must be born spiritually. You take the analogy too far.
What you don't get is "the how."
What did Jesus mean when he said:
Joh 3:5 Jesus answered, Verily, verily, I say unto thee, Except a man be born of water and of the Spirit, he cannot enter into the kingdom of God.
--There are only two elements mentioned here, both of which are necessary to the new birth or salvation.
One must be born of the Spirit. We all agree on that.
But what does it mean to be born of "water"? Many theories have been offered. Obviously we reject the RCC idea of baptismal regeneration.
Instead of going through the various theories, I will simply tell you what I believe and why.
"Water" is symbolic of the "Word."
Nicodemus was probably standing in sight of the Temple where he could view the many ceremonial cleansings of the Jews.
The most common purpose of water is for cleansing.
Jesus said in John 15:3:
Joh 15:3 Now ye are clean through the word which I have spoken unto you.
--Water cleanses; the Word cleanses.
Nicodemus knew this from the OT.
Psa 119:9 Wherewithal shall a young man cleanse his way? by taking heed thereto according to thy word.
--It is the Word that cleanses our way. Nicodemus knew that.
Jas 1:18 Of his own will begat he us with the word of truth, that we should be a kind of firstfruits of his creatures.
--Here James uses the word "begat" or "born". We are "born" of the Word.
The Word of God is imperative in the New Birth.
And even more clearly in 1Pet.1:23,
1Pe 1:23 Being
born again, not of corruptible seed, but of incorruptible,
by the word of God, which liveth and abideth for ever.
--It is abundantly clear that one is born again by the Word of God.
Water cleanses. The Word cleanses. Water is symbolic of the Word.
There are two and only two elements necessary for the new birth: (water and the Spirit) or The Word and The Spirit.
One is born again by the Spirit of God.
One is born again by the Word of God.
Both are necessary. If the Word of God is not preached the person cannot be born again. There must be belief in that Word (and conviction by the Holy Spirit) in order for the person to be born again).
The ministry of the Holy Spirit is clearly spelled out in John 16:8-11.