And in the beginning of the apostles teaching the gospel it was word of mouth. Nothing written down about that for many years.
The Apostles preached from the word of God (OT), even from Acts at Pentecost. There were many scribes that recorded what they said on various occasions, both amongst themselves and outside of themselves.
Mat_21:42 Jesus saith unto them, Did ye never
read in the scriptures, The stone which the builders rejected, the same is become the head of the corner: this is the Lord's doing, and it is marvellous in our eyes?
Mat_22:29 Jesus answered and said unto them, Ye do err, not
knowing the scriptures, nor the power of God.
Luk 4:16 And he came to Nazareth, where he had been brought up: and, as his custom was, he went into the synagogue on the sabbath day, and
stood up for to read.
Luk 4:17 And there was delivered unto him
the book of the prophet Esaias. And when he had
opened the book, he found the place where it was written,
Luk 4:18 The Spirit of the Lord is upon me, because he hath anointed me to preach the gospel to the poor; he hath sent me to heal the brokenhearted, to preach deliverance to the captives, and recovering of sight to the blind, to set at liberty them that are bruised,
Luk 4:19 To preach the acceptable year of the Lord.
Luk 4:20 And he closed
the book, and he gave it again to the minister, and sat down. And the eyes of all them that were in the synagogue were fastened on him.
Luk 4:21 And he began to say unto them, This day is
this scripture fulfilled in your ears.
Luk_24:27 And
beginning at Moses and all the prophets, he expounded unto them
in all the scriptures the things concerning himself.
Luk_24:32 And they said one to another, Did not our heart burn within us, while he talked with us by the way, and while
he opened to us the scriptures?
Luk_24:45 Then
opened he their understanding, that they might understand the scriptures,
Joh_5:39
Search the scriptures; for in
them ye think ye have eternal life: and
they are
they which testify of me.
Act_1:16 Men and brethren,
this scripture must needs have been fulfilled, which the Holy Ghost by the mouth of David spake before concerning Judas, which was guide to them that took Jesus.
Act 2:16 But
this is that which was spoken by the prophet Joel;
Act 2:25
For David speaketh concerning him, I foresaw the Lord always before my face, for he is on my right hand, that I should not be moved:
Act_8:32
The place of the scripture which he read was this, He was led as a sheep to the slaughter; and like a lamb dumb before his shearer, so opened he not his mouth:
Act_8:35 Then
Philip opened his mouth, and began at the same scripture, and preached unto him Jesus.
Act_17:2 And Paul, as his manner was, went in unto them, and three sabbath days
reasoned with them out of the scriptures,
Act_17:11 These were more noble than those in Thessalonica, in that they received
the word with all readiness of mind, and
searched the scriptures daily, whether those things were so.
Act_18:24 And a certain Jew named Apollos, born at Alexandria, an eloquent man, and
mighty in the scriptures, came to Ephesus.
Rom_4:3 For
what saith the scripture? Abraham believed God, and it was counted unto him for righteousness.
Rom_9:17 For
the scripture saith unto Pharaoh, Even for this same purpose have I raised thee up, that I might shew my power in thee, and that my name might be declared throughout all the earth.
Rom_10:11 For
the scripture saith, Whosoever believeth on him shall not be ashamed.
Rom_11:2 God hath not cast away his people which he foreknew. Wot ye not
what the scripture saith of Elias? how he maketh intercession to God against Israel, saying,
Rom_15:4 For
whatsoever things were written aforetime were written for our learning, that we through patience and comfort of the
scriptures might have hope.
Rom_16:26 But now is made manifest, and by
the scriptures of the prophets, according to the commandment of the everlasting God, made known to all nations for the obedience of faith:
1Co_15:3 For I delivered unto you first of all that which I also received, how that Christ died for our sins
according to the scriptures;
1Co_15:4 And that he was buried, and that he rose again the third day
according to the scriptures:
Gal_3:8 And
the scripture, foreseeing that God would justify the heathen through faith, preached before the gospel unto Abraham, saying, In thee shall all nations be blessed.
Gal_3:22 But
the scripture hath concluded all under sin, that the promise by faith of Jesus Christ might be given to them that believe.
Gal_4:30
Nevertheless what saith the scripture? Cast out the bondwoman and her son: for the son of the bondwoman shall not be heir with the son of the freewoman.
1Ti_5:18 For
the scripture saith, Thou shalt not muzzle the ox that treadeth out the corn. And, The labourer is worthy of his reward.
2Ti_3:15 And that
from a child thou hast known the holy scriptures, which are able to make thee wise unto salvation through faith which is in Christ Jesus.
2Ti_3:16
All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness:
Jas_2:8 If ye fulfil the royal law
according to the scripture, Thou shalt love thy neighbour as thyself, ye do well:
Jas_2:23 And
the scripture was fulfilled which saith, Abraham believed God, and it was imputed unto him for righteousness: and he was called the Friend of God.
Jas_4:5 Do ye think that
the scripture saith in vain, The spirit that dwelleth in us lusteth to envy?
1Pe_1:16
Because it is written, Be ye holy; for I am holy.
1Pe_2:6 Wherefore also
it is contained in the scripture, Behold, I lay in Sion a chief corner stone, elect, precious: and he that believeth on him shall not be confounded.
2Pe_1:20 Knowing this first, that no prophecy
of the scripture is of any private interpretation.
2Pe_3:16
As also in all his epistles, speaking in them of these things; in which are some things hard to be understood, which they that are unlearned and unstable wrest, as they do
also the other scriptures, unto their own destruction.
Mar_12:32 And
the scribe said unto him, Well, Master, thou hast said the truth: for there is one God; and there is none other but he:
Act_4:5 And it came to pass on the morrow, that their rulers, and elders, and
scribes,
Act_6:12 And they stirred up the people, and the elders, and
the scribes, and came upon him, and caught him, and brought him to the council,
Act_23:9 And there arose a great cry: and
the scribes that were of the Pharisees' part arose, and strove, saying, We find no evil in this man: but if a spirit or an angel hath spoken to him, let us not fight against God.