Michael Rowntree recently posted a short addressing Deion Sanders speaking in tongues at a press conference, and pointed to Paul's instruction that tongues shouldn't be spoken in the congregation with an unbeliever present unless an interpreter is there too, so the unbeliever isn't left thinking you've lost your mind (1 Corinthians 14:23, 14:27-28).

Comments came fast: isn't there a difference between tongues spoken publicly in a church service and a private prayer language used to build yourself up (1 Corinthians 14:4)? And what about in Acts when people are speaking in tongues with no interpreter?

Was Deion praying in a private prayer language, or was he doing what Paul describes as speaking in tongues in church (in public) in front of a mix of believers and unbelievers, where the interpretation rule applies?

Joshua Lewis, Michael Miller, and Michael Rowntree will answer the comments, working through 1 Corinthians 14 and the book of Acts.