Where in the world do you get your inference from? You are asking questions with no answer.
When one sins, the moment one makes the choice to sin, they are not ‘Christian’ meaning a follower of Christ.
I believe Paul after his revelation was a Christian but aware of the constant temptation to be unChristian. He had to train his every thought, every feeling on communing with Jesus. One lapse and he would fall to sin. He was battling sin with every breath. He knew the temptation was outside and inside but he chose not to succumb to it, at least that is my take.
The subject that started this discussion is from Ann Coulter’s implication that the world would be better off if everyone was Christian. It’s an impossibility because even fervent Christians have difficulty following Christ in all they do. So her thought is impractical and unrealistic. At what moment do all souls flash to true Christianity?
What is practical is to practice Christian values and to vote American values. That is the winning combination.
It would have been far more realistic if Coulter had modified her assertion that the world would be better off if people would earnestly strive to learn about Christ and practice Christian values.
In fact, she's not a minister at all.
We are born with a sinful nature. We sin in thought and in deed and yes, we can prevent a lot of it, but when we sin we are still Christian, saved by grace, and able to nullify the sin by seeking God’s face for forgiveness. He tells us if we confess our sins, He will forgive us our sins. We’re still Christians, however.