2 Corinthians 11:5-6
For I consider that I am not at all inferior to the most eminent apostles. Even though I am untrained in speech, yet I am not in knowledge. But we have been thoroughly manifested among you in all things.

Link: bible-illustrated.blogspot.rs/2016/07/2Cor1105.html

Thank you, Fr. Branko, for making this illustration possible!