Adam Clarke on 1 Corinthians 1:24

But unto them which are called - Τοις κλητοις. Those, both of Jews and Greeks, who were by the preaching of the Gospel called or invited to the marriage feast, and have accordingly believed in Christ Jesus; they prove this doctrine to be divinely powerful, to enlighten and convert the soul, and to be a proof of God's infinite wisdom, which has found out such an effectual way to glorify both his justice and mercy, and save, to the uttermost, all that come to him through Christ Jesus. The called, or invited, κλητοι, is a title of genuine Christians, and is frequently used in the New Testament. Ἁγιοι, saints, is used in the same sense.