Your confusion arises from the assumption that the process is too long to have completed for anyone. The key is this: the process is already completed in one sense, but not yet in another sense!!! Let me explain.
I AM already a bona fide born-again christian, which means that after a PROCESS (NOT merely a point event) of God's enabling and regenerating power of the holy spirit, I had come to a climactic point (Yes, a point event here) where I responded in spirit-led faith to accept God's gracious gift of salvation in Christ Jesus. Thus, my faith grew little by little during this process, until it exceeded the thresh point required of God for my salvation. You may say that I have finally had "enough" faith for my justification (being credited to be righteous on account of Jesus Christ my Savior and Lord).
Then, I am BEING a bona fide born-again christian, meaning that I am still being regenerated daily by the life-changing power of the holy spirit so that I continually live out a God-glorifying life imitating Christ. Thus, from faith to faith (Romans 1:17), I am building up my faith daily. The faith that once saved me from the horrific penalty of sin continues to save me from both the penalty AND the power of sin, in other words, it continue to help me to "work out" my salvation (see Ephesians 2:12b). I am being sanctified by obedience to the holy spirit in faith.
Finally, I WILL have been a bona fide born-again christian when I fold up my tent of life on this planet and get ready for the glorious day of resurrection in the second coming of the Lord Jesus. Thus, my faith will be rewarded big time for me both in this life and in eternity! Praise the Lord!
In retrospect, this whole thing of my salvation has been started in time BEFORE time when God predestines me to be a vessel for his blessing. What a lucky man I am!
Hope you get the same blessing. God bless.