1 Corinthians comes next, written from Ephesus to Corinth on Paul's "third missionary journey."
Paul calls them "sanctified" (1:2) and implies that God can keep them "guiltless" (anenkletos) until the end (1:8). Given the profile of the Corinthians elsewhere, this cannot involve complete moral perfection. This is something to keep in mind as we move through the letter.
Of note is that God's choice of the weak shows His strength. We have no basis on which to boast before God (1:29). We are to boast in the Lord (1:31). Christ is our "wisdom from God, and righteousness, and sanctification, and redemption" (1:30). What Paul means is that the cross defines true wisdom over and against the wisdom of the "Greeks." Christ provides the only effective path to justification or righteousness. Christ is the one who can put us in the state of belonging to God. And Christ is the one who has redeemed us from our sins.
1 Corinthians 1 thus plays into a positional sense of holiness and righteousness, although as we have seen and will see, it does not contradict a requirement for true righteousness for believers as well.