Perhaps you have met such ones as you engage in the field ministry. Some are even able to recite Bible passages from memory.
وَلَعَلَّكَ ٱلْتَقَيْتَ أُنَاسًا كَهٰؤُلَاءِ أَثْنَاءَ خِدْمَتِكَ فِي ٱلْمُقَاطَعَةِ .‏