God renewed your SPIRIT, ...as Born again, that became a ETERNAL... """NEW CREATION>..In Christ.""""""
But He did not renew your mind.
You are told to do that... and until you do, you will think you are a sinner, sinning, and might lose your salvation, and a Cult will get you and destroy your Christianity.
Hebrews 13:9
So, the process of giving you Eternal Salvation , fell to God, and He did it through the Cross of Christ for you as "the gift of Salvation", 2000 yrs ago.
He saved you...= BORN AGAIN...... Finished Salvation.
Now, you are in the process, (if you are born again, and not just water baptized)....of perfecting your discipleship by renewing your mind, which is to "work out your Salvation"
Not earn it....but "work IT out.".
You've read that you are to "work out your salvation"...and that does not mean to try to keep from losing it, as a Religious Legalist will teach you.
But rather this means that you are to learn how to exist correctly within the Salvation that God has provided you, as a Gift, through the Cross of Christ.
If you are born again, you are IN The Kingdom of God already.. And now you have to learn how to exit there, by REAL faith, that is the RENEWED mind.
This is why God sends a real teacher.
You have to learn.
Listen.........>"Jesus LEARNED obedience by the Things HE SUFFERED", and you have to learn the New Testament, and that is why God gives, Pastors, Teachers, Apostles, Prophets, ... all of this.......so that you can be "Faith Perfected", or, you'll just stumble and fall, and be confused and find frustration and worry.
So, when you read an Apostle talking to unbelievers, He'll talk to them about their SIN.
About getting rid of it, by confessing, which is what most people do, when they are getting saved.
They ADMIT they are horrible, sinners, lost,.....needing Christ.
"REPENTING".... and "Believing".
Turning from unbelief TO FAITH.