If you read the entire passage, it's very clear who Paul is talking about in I Corinthians:
Do you not know that the unrighteous will not inherit the kingdom of God? Do not be deceived: neither the sexually immoral, nor idolaters, nor adulterers, nor men who practice homosexuality, nor thieves, nor the greedy, nor drunkards, nor revilers, nor swindlers will inherit the kingdom of God. And such were some of you. But you were washed, you were sanctified, you were justified in the name of the Lord Jesus Christ and by the Spirit of our God.
Paul is talking of the 'unrighteous' in that passage because then he says "such were some of you". There is a big difference in before and after.