Nazaroo,
Wouldn't it be great if we could get all the good people over here and round up the bad people over there?
Then all we would need to do is destroy those bad people once and for all, and then the world could finally be in peace.
Its not a black and white situation,
but there is definitely a scale of goodness, as demarcated in the bible.
You can be good enough to escape judgement:
Just do your best and sincerely try to understand Jesus' teaching and follow Him.
What you are talking about (separation of good and evil)
is happening automatically,
and will happen with greater extent and in a more extreme fashion soon,
just as Jesus predicted and the prophets wrote it would be.
Those who don't belong on Christian lands will return to the lands of their fathers.
The meek will inherit the earth, sans the violent and wicked.
Whether or not they are destroyed there will be in part determined
by their hearts, i.e., why they returned.
For instance,
those who either return to the Middle East to join a war
against Israel,
or those who simply turn away from the truth of Christ,
and
go and join radical groups of violent men,
will both be destroyed together,
as Jesus and the Bible foretold.
Clay and Iron will not mix, and the
sheep and goats will be separated
by the LORD Himself.
We don't need to do the separating.
But that line between good and evil runs down the center of every human heart.
And no one wants to destroy a piece of their own heart, do they?
A large part of this false hyper-Protestant dogma is based on
an exaggerating and taking out of context Pauline thought.
For instance, when Paul describes his former self in Romans,
unable to control his own desires, he is talking about the natural
unsaved man,
not about born-again Christians who are given power to overcome sin,
and become free of the bondage of sin.
Also,
I take issue with your final semi-rhetorical question,
which actually makes no sense in the experience of a regenerated Christian.
On the one hand, if I have a cancer, or darkened part of my body,
I will willingly have it removed or have God make it disappear,
and I will not miss it.
As Jesus wrote, it is better to enter into life (the Kingdom of God)
with one hand than be cast into the Lake of Fire with both hands.
The Christian should have the same heart and mind as Jesus Christ.
"If you are willing Lord, you can make me clean (remove cancer),
and make me whole (replace missing or crippled limbs), (Luke 5:2, Mk 1:40, Matt 8:2)
and make me see (cure a lifetime of blindness)." (John 9, Mk 8:22, Lk 18:35)
Your final sentiment is incompatible with Christianity.
Your rhetorical question has an answer opposite to your premise.