[circlecity]

"as you cannot really sin and repent at the same time."

Not sure what you mean here. Certainly one cannot be sincerely repentant and continue to live in sin. But, even the most repentant will still commit sins. This is why repentance is a continuous process, not a one time act.

[Dr. Sivana]

But, even the most repentant will still commit sins.

So, between the time you sin and the time you repent of the sin, you are still a Christian, even if you are a Christian in bad standing.