Paul addressed all of them as saved because his epistle was written to
“the church of God which is at Corinth, to those who have been sanctified in Christ Jesus, saints by calling, with all who in every place call on the name of our Lord Jesus Christ, their Lord and ours:”
1 Corinthians 1:2 NASB
And Paul says to these saints
“And I, brethren, could not speak to you as to spiritual men, but as to men of flesh, as to infants in Christ. I gave you milk to drink, not solid food; for you were not yet able to receive it. Indeed, even now you are not yet able, for you are still fleshly. For since there is jealousy and strife among you, are you not fleshly, and are you not walking like mere men?”
1 Corinthians 3:1-3 NASB
These “who have been sanctified in Christ are still fleshly and yet they have repented. They are still new Christians and still have much to learn which takes time which is what Paul is saying in chapter 2. Nobody is baptized coming out of the water suddenly understanding all that the Spirit has to teach. So your statement that the carnal man cannot repent is false because 1 Corinthians is a prime example of carnal people who have repented.