1 Corinthians 6:11
And such were some of you: but ye are washed, but ye are sanctified, but ye are justified in the name of the Lord Jesus, and by the Spirit of our God.
For all Christians, any sin is forgiven. And, any sin is forgivable (including those in the previous verses). In the context, for this Jewish congregation, Paul is telling them that their forgiveness not only gives them everlasting life but makes them whole for the future kingdom.
When it comes to salvation (not kingdom inheritance) all those who believe, Jew or Greek, are washed, sanctified, and justified. These are all one time, once and for all events in the name of the Lord Jesus, and by the Spirit of our God.