Your language may have a particular way of introducing the author of a letter and the intended audience. Alternate translation: "I, Paul, wrote this letter to you in Corinth who believe in God"
Here "sanctified" refers to people whom God has reserved to honor him. Alternate translation: "to those whom Christ Jesus has set apart for God" or "to those whom God has set apart for himself because they belong to Christ Jesus"
This can be stated in active form. Alternate translation: "whom God has called to be holy people" (See: [[rc://en/ta/man/translate/figs-activepassive]])
"Name" here is a metonym for person of Jesus Christ. Alternate translation: "who call on the Lord Jesus Christ" (See: [[rc://en/ta/man/translate/figs-metonymy]])
The word "ours" includes Paul's audience. Jesus is the Lord of Paul and the Corinthians and all the churches. (See: [[rc://en/ta/man/translate/figs-inclusive]])