1 Corinthians 14:24

But if all prophesy, and there come in one unbelieving or unlearned, he is reproved by all, he is judged by all;

'if all prophesy' -The visitor is convicted by the preaching of the prophet(s), because the prophet spoke in the language of the assembly, which would of also been the language of the city and it's inhabitants. The visitor is convicted because he/she understands the preaching.

'reproved by all' -'convicted by all' (NASV) 'called to account..Lying behind the word "convicted" is the OT view that one is exposed before the living God through the prophetic word '; inherent in such "exposure" is the call to repentance, the summons to have one's exposed sins forgiven by. merciful God.' (Fee p. 686) (John 16:8; Ephesians 5:11; Ephesians 5:13; Titus 1:9; 2 Timothy 4:2)

'judged by all' -'Examined..the word implies inquiry rather than sentence.' (Vincent p. 271) 'Question after question strikes home and reveals his sin and his guilt to him.' (Lenski p. 604) 'all these sermons will convince him of the fact that he is. sinner, and his conscience will be pricked by everything he hears.' (Tay)

Point to Note:

Here is Paul's view of the type of preaching and or teaching that needs to be found in the assembly of the saints. Lessons that would convict the hearts of men. If. sinner goes away feeling good and yet still in his sins, the lesson failed to accomplish God's desire.