Catholic Encyclopedia > F > The Faithful
https://www.newadvent.org/cathen/05769a.htmThe Faithful
Those who have bound themselves to a religious association, whose doctrine they accept, and into whose rites they have been initiated. Among Christians the term is applied to those who have been fully initiated by baptism
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Strictly speaking, therefore, the term faithful is opposed to catechumen; hence, it is not met in the writings of these early Christian Fathers who flourished before the organization of the catechumenate. It is not found in St. Justin nor in St. Irenæus of Lyons;
Tertullian, however, uses it, and reproaches the heretics for obliterating all distinction between catechumens and the faithful: quis catechumenus, quis fidelis incertum est (De praeser., c. xli; P.L., II, 56).
Henceforth, in the patristic writings and canons of councils we meet quite frequently the antithesis of catechumens and baptized Christians, Christians and faithful.
Thus St. Augustine (Tract. in Joannem, xliv, 2; P.L., XXXV, 1714): "Ask a man: are you a Christian? If he be a pagan or a Jew, he will reply: I am not a Christian. But if he say: I am a Christian, ask him again: are you a catechumen, or one of the faithful?"
Tertullian
Prescription against Heretics
Chapter 41
https://www.newadvent.org/fathers/0311.htmI must not omit an account of the conduct also of the heretics— how frivolous it is, how worldly, how merely human, without seriousness, without authority, without discipline, as suits their creed. To begin with, it is doubtful who is a catechumen, and who a believer; they have all access alike, they hear alike, they pray alike — even heathens, if any such happen to come among them.
St. Augustine
Tractates on the Gospel of John
Tractate 44 (John 9)
https://www.newadvent.org/fathers/1701044.htm2. The Lord came: what did He do? He set forth a great mystery. "He spat on the ground," He made clay of His spittle; for the Word was made flesh. "And He anointed the eyes of the blind man." The anointing had taken place, and yet he saw not. He sent him to the pool which is called Siloam. But it was the evangelist's concern to call our attention to the name of this pool; and he adds, "Which is interpreted, Sent." You understand now who it is that was sent; for had He not been sent, none of us would have been set free from iniquity. Accordingly he washed his eyes in that pool which is interpreted, Sent — he was baptized in Christ. If, therefore, when He baptized him in a manner in Himself, He then enlightened him; when He anointed Him, perhaps He made him a catechumen. In many different ways indeed may the profound meaning of such a sacramental act be set forth and handled; but let this suffice your Charity. You have heard a great mystery.
Ask a man, Are you a Christian? His answer to you is, I am not, if he is a pagan or a Jew. But if he says, I am; you inquire again of him, Are you a catechumen or a believer? If he reply, A catechumen; he has been anointed, but not yet washed.
But how anointed? Inquire, and he will answer you. Inquire of him in whom he believes. In that very respect in which he is a catechumen he says, In Christ. See, I am speaking in a way both to the faithful and to catechumens. What have I said of the spittle and the clay? That the Word was made flesh. This even catechumens hear; but that to which they have been anointed is not all they need; let them hasten to the font if they are in search of enlightenment.