I believe what the Bible says:
We all began in wickedness:
Eph. 2:1-3 "
And you were dead in your trespasses and sins, in which you formerly walked according to the course of this world, according to the prince of the power of the air, of the spirit that is now working in the sons of disobedience. Among them we too all formerly lived in the lusts of our flesh, indulging the desires of the flesh and of the mind, and were by nature children of wrath, even as the rest."
And then God graciously caused us to hear the gospel and obey it:
Eph. 2:4-6 "
But God, being rich in mercy, because of His great love with which He loved us, even when we were dead in our transgressions, made us alive together with Christ (by grace you have been saved), and raised us up with Him, and seated us with Him in the heavenly places in Christ Jesus."
It's all the work of God, just as Eph. 2:8 tells us it is:
"
For by grace you have been saved through faith; and that not of yourselves, it is the gift of God."
If you are looking for a chronology, then Eph. 1:4 must be included:
"
He chose us in Him before the foundation of the world..."
So the chronology is: God elected some to be in Christ before anyone existed, then the human race came into existence with a fallen nature, in which we all started out that way (and in which many continue), then God converts those elected before they existed through the gospel at various times, and those people believe and are saved. Then in the end at the 2nd advent, all the elect, both dead and living, through the resurrection and translation of the physical nature, will be gathered "from the four winds" to be with Christ forever.
TD