Luke's Gospel: "That thou mayest know the verity of those things in which thou hast been instructed" (] him, in all good things" (Galatians 6:6).Hence the word, with its technical meaning of oral religious instruction, passed into ecclesiastical use, and is applied both to the act of instructing and the subject-matter of the instruction.
The Socratic dialogues will occur to every one as brilliant examples.
But many centuries before Socrates' day this method was practised among the Hebrews (Exodus ; Deuteronomy 6:7, 20, etc.). In His final charge to His Apostles He said: ", "instructing"] them to observe all things whatsoever I have commanded you" (Matthew ).
They had three forms of catechizing: domestic, conducted by the head of the family for the benefit of his children and servants; scholastic, by teachers in schools; and ecclesiastical by priests and Levites in the Temple and the synagogues. And after this instruction they were to initiate them into the Church, "baptizing them in the name of the Father, and of the Son, and of the Holy Ghost" (ibid.). Peter, "standing up with the eleven", declared to the Jews on Pentecost day, and proved to them from the Scriptures that Jesus, whom they had crucified, was "Lord and Christ". in the name of Jesus Christ, for the remission of your sins." "And with very many other words did he testify and exhort them" (Acts 2).
Proselytes were carefully instructed before being admitted to become members of the Jewish faith. When they had been convinced of this truth, and had compunction in their heart for their crime, they asked, "What shall we do? We have here an abridgment of the first catechetical instruction given by the Apostles. John came from Jerusalem and "prayed for them, that they might receive the Holy Ghost"; and doubtless declared to them the doctrine of that Holy Spirit (ibid.).
As we might expect, the Apostle insists upon "doctrine" as one of the most important duties of a bishop (1 Timothy , 16; ; 2 Timothy 4:2, etc.).
The word means instruction by word of mouth, especially by questioning and answering.
Him God raised up the third day, and gave him to be made manifest . To him all the prophets give testimony, that by his name all receive remission of sins, who believe in him" (Acts 10).
In this discourse we have the chief articles of the Creed: the Trinity (God, Jesus Christ "Lord of all things", the Holy Ghost), the Crucifixion, Death, and Resurrection of Our Lord; His coming to judge the living and the dead, and the remission of sins. Paul's discourses, though, of course, in addressing the pagans, whether peasants at Lystra or philosophers at Athens, he deals with the fundamental truths of the existence and attributes of God (Acts, xiii, xiv, xvii).
When addressing a mere inquirer they would naturally be more guarded and less explicit than if they had to do with one who had passed through the catechumenate. The "Procatechesis" and the eighteen discourses were intended for the during Lent, in immediate preparation for reception into the Church.