1 Corinthians 12:3 (ESV)

3 Therefore I want you to understand that no one speaking in the Spirit of God ever says “Jesus is accursed!” and no one can say “Jesus is Lord” except in the Holy Spirit.

How can the Spirit’s work be identified in a person’s life? Not so much by his spiritual gifts (a topic to which Paul will come in 1 Corinthians 12:4), but by his confession of Jesus as Lord (see also 1 Corinthians 2:10–15).

The word accursed (anathema) is a typically Jewish word. It is used in the Septuagint (the ancient Greek translation of the Hebrew Scriptures) to refer to things that are under the ban (or devoted to destruction; see, e.g., Exodus 22:20; Deuteronomy 13:15). Israelites who openly worshipped other gods, or took God’s devoted things for themselves, were placed under the ban. They and everything that belonged to them had to be destroyed.

Possibly there were Jews in Corinth who were calling Jesus accursed (or, perhaps a better translation, under the ban). From Acts 18:1–28 we know that many Corinthian Jews were vehemently opposed to the gospel. Those Jews who were led by the Spirit to confess Jesus as Lord had no option but to leave the synagogue.

To confess Jesus as Lord was not merely to honour him as one’s king or leader. It was to confess him as Yahweh, the God of Israel (see Philippians 2:9–11). The confession that Jesus is Lord may be the oldest confession in the history of the church (see, e.g., John 13:13; Romans 10:9; Philippians 2:11). Especially when faced with so much opposition, such a confession was (and still is) a sign of the Spirit’s work in a person’s life. Yet, as Jesus warned, it needed to come from the heart (Matthew 7:21–23).