In 1 Corinthians 14, Paul was establishing some basic guidelines that would help bring order to the disorderly meetings the Corinthian believers were having. In this passage he is telling those who prophesy that they should not all speak at the same time but in turn (vs.31). He then tells them that their spirits (i.e. their voices) are subject to them. In other words, he is taking away the excuse that 'I couldn't help myself, the Holy Spirit just took me over.' Paul knew that the Holy Spirit does not operate this way. The Holy Spirit is very gentle. The problem was that the Corinthian prophets were not controling themselves but were speaking out impulsively without giving any consideration as to what else may be going on at the time. So Paul's statement in verse 32 is simply telling the prophets that they are responsible for exercising self-control and only speaking out at the appropriate time. As Proverbs 25:28 says, 'Whoever has no rule over his own spirit is like a city broken down, without walls.'