There is no such doctrine in the Scriptures of becoming saved over a period of time. Salvation is a one time event by those who accept God's offer of Salvation. The word Salvation can also refer to our Sanctification, which is our ongoing progression in becoming more Christ-like. Salvation, when referring to when someone actually gets saved, is not a process, it is single event which happens when the person accepts Christ as his savior at a specific time and place.Our salvation from sin would be incomplete if we were only saved from the penalty of our sin while our lives continued to be directed at being doers of sin, so there must be an aspect of our gift of salvation that we are experiencing in the present by repenting and directing our lives towards being a doer of God's law. In Titus 2:11-13, our salvation is described as being trained by grace to do what is godly, righteous, and good, and to renounce doing what is ungodly, so God graciously teaching us to experience being a doer of those works is the way that He is giving us his gift of salvation. So if our lives are directed at being a doer of God's law, then that is how we know that we are being saved.
If you don't make this distinction between Salvation and Sanctification, you likely will take on the false teaching of salvation by works. I might add this passage from Rom 11.32 to help answer why we are all condemned. God condemned us all so he could have mercy on all. So, God condemning mankind was a blessing in disguise.