Note 1 at 1Co 14:23: Tongues benefited the church only if they were interpreted (see note 12 at 1Co 14:5). Even though they benefited the individual users (see note 4 at 1Co 14:2), the goal of the church service was to be edification for all (see note 16 at 1Co 14:12). It seems that some of the Corinthians didn't understand this principle. Therefore, Paul was writing not to discourage spiritual gifts but rather to instruct that their goal in the church was to be the edification of others (see note 1 at 1Co 14:1).

Note 2 at 1Co 14:23: Paul was stating that if all are speaking in unknown tongues in the church service and people come in who are either unlearned or unbelievers, they will conclude that these people are insane and suffer from a disorder of the mind.

The Greek word for "unlearned" in this passage is "IDIOTES," from which we derive the English word "idiot." It is simply denoting someone who is ignorant of this gift of speaking in tongues, and was translated "ignorant" in Ac 4:13.

Note 3 at 1Co 14:23: The Greek word that was translated "unbelievers" here is "APISTOS." This is a compound word consisting of "PISTOS" and "A." PISTOS is the adjective form of "PISTIS," the Greek word for faith, and A is being used here as a negative particle (Strong's Concordance). Therefore, this is describing someone who is against speaking in tongues or doesn't believe in it.