1 Corinthians 12:1-3

There is a difference in a person's life before they are saved and after they are saved. Before, those Paul is addressing are those who were led astray by idols. However, he wants to make the point that one speaking in the Spirit of God cannot say "Jesus is accursed" and it is only in the Holy Spirit that one can say "Jesus is Lord". In 1 John there is a similar point made with regards to testing the spirits. In Paul's case here in 1 Corinthians, he is about to talk about gifts of the Spirit.