The New Birth, like the old one of the flesh, is not an abstract principle, but a process. It begins with the begettal and ends with the having been born. A son of God is a character which is developed out of the 'incorruptible seed' of God, sown into the fleshly table of the heart.
When this seed, or word of the Kingdom, is received, it begins to work in a man until he becomes a believer of the truth. When things have come to this pass, he is a changed man. He has acquired a new mode of thinking, for he thinks in harmony with the thoughts of God as revealed in His law and testimony. He sees himself and the world around him in a new light. He is convinced of sin; and experiences an aversion to the things in which he formerly delighted. His views, disposition, temper and affections are transformed. He is humble, child-like, teachable, and obediently disposed; and his simple anxiety is to know what God would have him do. Having ascertained this, he does it; and in doing it, is 'born out of the water.' Having been begotten by the Father by the Word of truth, and born of water, the first stage of the process is completed.
J. Thomas.
Then comes a life time of putting on the 'mind of Christ'. Our re-birth is indeed a process as Bro Thomas writes. Paul states:
"....put off concerning the former conversation the old man, which is corrupt according to the deceitful lusts; And be renewed in the spirit of your mind; And that ye put on the new man, which after God is created in righteousness and true holiness" Eph 4:22-24
and
"...ye have put off the old man with his deeds; And have put on the new man, which is renewed in knowledge after the image of him that created him: Where there is neither Greek nor Jew, circumcision nor uncircumcision, Barbarian, Scythian, bond nor free: but Christ is all, and in all. Put on therefore, as the elect of God, holy and beloved, bowels of mercies, kindness, humbleness of mind, meekness, longsuffering; Forbearing one another, and forgiving one another, if any man have a quarrel against any: even as Christ forgave you, so also do ye." Col 3:9-13
May none of us be 'still born', but rather may we hold fast to that which is good, holding on to sound doctrine in these last days. If we do then according to the great mercy of God in us the latter stages of the process may find completion and we shall be raised incorruptible.