I think I know what you are saying, but disagree with your terminology. The new birth is an event, not a process. If there is any process that follows, then fine. But that is subsequent to being born again. It is not process that causes one to be born again. Your initial birth into this world was also an event. There is a process of life afterward, but it is not called the birth process.
The new man does not turn away. Paul told the Ephesians to put off the old man and put on the new man. If I follow this advise, then there is a part of me that is doing the putting off of the one and putting on the other. That part of me is ME. I am a soul. The word comes from psyche. It basically means the mind. If I am the one putting on the new man, then I would be the one also falling away.
The new man is merely the new nature within me, in my spirit. The new birth is the giving and receiving of this new nature within our spirit. Thus a new man is created in me (Eph.4:24). That which is born of the Spirit IS spirit, not soul.
However, I would not venture to say that one is deliberately choosing to walk away from eternal life. The Galatians for example, were told that they had fallen from grace. This was not a choice on their part to walk away from justification, but rather the result of being duped into going back to justification by law. There are many who appear to walk away from Christ, but we are told that they never were of Him or in Him in the first place.
Here you go again, telling us what you think willful sin is. As I said before, there is only one reference in scripture for this term. Your commentary on it has no basis in the context from which it is taken. The last verse in the chapter indicates that it is intertwined with unbelief. Therefore it does not apply to a born again believer in sin, willful or otherwise.
But if you insist that a refusal to be obedient to Christ will cause you to lose salvation, then I might ask if you think that He will judge you for not obeying Him. I say this because in John 5:24, Jesus promised that those who are of faith in Him will not come into judgment. So if we lose our life, it will not be as a result of having been judged...unless we fall completely out of the faith that protects us from judgment. Please read that reference for yourself if you don't agree.
With all due respect, and I mean that sincerely, what a silly comment! Who on earth would have the mindset to murder people to stay in favor with God? let's rather talk sensibly about this subject rather than use ridiculous examples.

Having said that, I absolutely agree that we love Him because He first loved us. I absolutely agree that the fruit we bear is a result of that which he has placed within us in the new birth, by faith. But the new birth is essential. Otherwise a person is simply obeying God from out of his own Adamic nature. This will not be acceptable to God. The law is in our hearts because He put it there when He gave us His own righteousness. There is no need for any commandments. His love is in the new man. The law in our hearts is the new nature within us. It is the unrighteous, not the righteous, that need laws.
But allow me to comment on law for a second. The thing which makes law relevant as law, is enforcement. Otherwise it is merely a rule. Imagine if the police went on strike, how much crime would follow. Enforcement is essential in law. And in the case of God's moral law, the enforcement is death. That enforcement was put on Jesus on our behalf, and is placed onto us, in our old man, by proxy through faith in Him. We have already died for sin. The old man is positionally dead with Christ. The Christian who sins is exempt from judgment to death (John 5:24), but not exempt from chastening to correction. Why is it that so many are forgetting about chastening?