It is the Spirit, that gives Life.

It is the Spirit who gives life; the flesh is no help at all. The words that I have spoken to you are spirit and life. - JOHN 6:63

Sinful man according to his flesh alone profits no spiritual good. That which is born of flesh is strictly flesh! It is the Spirit that gives life (makes one alive) in order that they, those who come to Christ after being born again may truly understand spiritual truths. This is why the Jews primarily took offense, because they could not discern spiritual truths that Christ spoke (john 6:25-65). The carnal man in his flesh cannot comprehend things pertaining to the Spirit (1 corinthians 2:14) but the one who has the Spirit in him from being born again now has the ability to understand the thoughts of God (1 corinthians 2:11-13). You won't and cannot believe apart from being made alive.

https://biblehub.com/greek/2227.htm

FURTHER EXAMINATION:

In verse 63, Jesus spoke truth saying, It is the Holy Spirit that makes one alive and the flesh to which men are born profits no spiritual good. He spoke of the flesh as having no help at all regarding the words He spoke. For He continues to say in verse 63, the words He spoke to the disciples following Him are of the Spirit of God or of God who is Spirit and pertain to spiritual life. He was stating a theological truth that man according to his flesh alone cannot ascertain spiritual truths. Spiritual truths are only understood by the Spirit or in essence, regeneration. In verse 64, Christ states, that there were some of them who did not believe. And finally in verse 65, He reiterates what He has already said in verse 44; that - "This is why I told you that no one can come to me unless it is granted him by the Father.” In other words, no can come to the Son unless (IT) has been granted to him by the Father - to come and believe on the Son. What is being granted is the ability to hear and learn from the Father by way of spiritual life or being made alive. Prior to this ability being granted, sinful man is unable (DUNAMI, verse 44 and 65) to come to Christ and believe - this ability has to be granted. And it is only granted to those given to the Son from the Father.

THE WORDS OF ETERNAL LIFE are for  only those who were PROMISED ETERNAL LIFE beforehand; Christ SHEEP!

By Aaron Fisher