SOURCES OF DOCTRINAL TIMELINE
If you are interested in reading the sources and/or quotes of the early Church Fathers on the doctrines above, here they are:
Timeline with Quotes
The book of Acts 15 records the first Christian Church Council. It took place in Jerusalem. This is a visible church with God’s appointed leadership deciding on laws for the whole church. It unilaterally said, without appealing to explicit Old Testament passages, that circumcision is out. This was not left for individual Christians to decide according to their consciences, it was law from then for Christians and letters were sent out to all the churches with this decree. The Church, begun by Christ and given His Holy Spirit guided the leaders in their decision.
The leader, after the death of St. Peter in Rome, was Linus (possibly referred to in II Tim. 4:21)
We know that St. John in his vision recorded in Revelation, saw the seven churches in Asia Minor as well as the church-planting of St. Paul. So at this time we know the church was spreading and that they were still under the authority of the Apostles and those the Apostles chose as leaders such as Timothy and Titus.
Confess your sins in church, and do not go up to your prayer with an evil conscience. This is the way of life. . . . On the Lord’s Day gather together, break bread, and give thanks, after confessing your transgressions so that your sacrifice may be pure. (Didache 4:14, 14:1).
Mary, Full of Grace
[T]he report concerning the child was noised abroad in Bethlehem. Some said, ‘The Virgin Mary has given birth before she was married two months.’ And many said, ‘She has not given birth; the midwife has not gone up to her, and we heard no cries of pain.’" (Ascension of Isaiah 11).
[Ten years later] So the Virgin became a mother with great mercies. And she labored and bore the Son, but without pain, because it did not occur without purpose. And she did not seek a midwife, because he caused her to give life. She bore as a strong man, with will . . . " (Odes of Solomon 19 [A.D. 80]).
Old Testament Canon (Septuagint with Deuterocanonical's or Apocrypha)
You shall not waver with regard to your decisions [Sirach 1:28]. Do not be someone who stretches out his hands to receive but withdraws them when it comes to giving [Sirach 4:31]" (Didache 4:5).
Confession (and denominations)
You shall not make a schism, but you shall pacify those that contend by bringing them together. You shall confess your sins. You shall not go to prayer with an evil conscience. This is the way of light. (Letter of Barnabas 19).
Old Testament Canon (Septuagint)
Since, therefore, [Christ] was about to be manifested and to suffer in the flesh, his suffering was foreshown. For the prophet speaks against evil, ‘Woe to their soul, because they have counseled an evil counsel against themselves’ [Is. 3:9], saying, ‘Let us bind the righteous man because he is displeasing to us’ [Wisdom 2:12.]" (Letter of Barnabas 6:7).
By the word of his might [God] established all things, and by his word he can overthrow them. ‘Who shall say to him, "What have you done?" or who shall resist the power of his strength?’ [Wisdom 12:12]" (Letter to the Corinthians 27:5 [ca. A.D. 80]).
Pre- AD 79
Pater Noster was the name of a mysterious Latin word square that has been found in many places from England to Mesopotamia. Two were found at Pompeii which would have to date back to before 79 AD when the city was destroyed.
Late first century...
Clement bishop of Rome, the companion of Paul mentioned in Philippians 4:3. With Paul in AD 57 in Phillipi. He assumed leadership position for church and wrote authoritative disciplinary letter to the people at Corinth.This Epistle was held in very great esteem by the early Church. The Epistle read in numerous churches, as being almost on a level with the canonical writings--in the Alexandrian ms., immediately after the inspired books. Clement of Rome wrote:
Our apostles also knew, through our Lord Jesus Christ, that there would be strife on the question of the bishop’s office. Therefore for this reason . . . they appointed the aforesaid persons and later made further provision that if they should fall asleep other tested men should succeed to their ministry" (Letter to the Corinthians, 44).
The apostles received the gospel for us from the Lord Jesus Christ: Jesus the Christ was sent from God. Thus Christ is from God, the apostles from Christ. In both cases the process was orderly and derived from the will of God. (Letter to the Corinthians, ch. 42)
Heresy: Docetism begins Belief that Jesus' physical body was an illusion, as was his crucifixion; that is, Jesus only seemed to have a physical body and to physically die, but in reality he was incorporeal, a pure spirit, and hence could not physically die
Intercession of those in Heaven
But those who are weak and slothful in prayer, hesitate to ask anything from the Lord; but the Lord is full of compassion, and gives without fail to all who ask him. But you, [Hermas,] having been strengthened by the holy angel [you saw], and having obtained from him such intercession, and not being slothful, why do not you ask of the Lord understanding, and receive it from him?’ (The Shepherd of Hermas 3:5:4).
Bishop of Antioch, Ignatius, wrote several letters instructing the members to “be submissive to the bishop and to one another as Jesus Christ was to the Father and the Apostles to Christ . . . that there may be unity.” He also wrote to the churches about the authority of the bishops and the supreme authority of Rome:
All of you follow the bishop as Jesus Christ followed the Father, and the presbytery as the apostles; respect the deacons as ordained by God. Let no one do anything that pertains to the church apart from the bishop. Let that be considered a valid Eucharist which is under the bishop or one who he has delegated . . . it is not permitted to baptize or hold a love feast independently of the bishop. (Letter to the Smyrnaeans, ch. 8)
Not as Peter and Paul did, do I command you [Romans]. They were apostles, and I am a convict" (Letter to the Romans 4:3). [Giving Rome primacy]
For as many as are of God and of Jesus Christ are also with the bishop. And as many as shall, in the exercise of penance, return into the unity of the Church, these, too, shall belong to God, that they may live according to Jesus Christ" (Letter to the Philadelphians 3).
Eucharist not symbolic
I have no taste for corruptible food nor for the pleasures of this life. I desire the bread of God, which is the flesh of Jesus Christ, who was of the seed of David; and for drink I desire his blood, which is love incorruptible. (Letter to the Romans 7:3).
Take note of those who hold heterodox opinions on the grace of Jesus Christ which has come to us, and see how contrary their opinions are to the mind of God. . . . They abstain from the Eucharist and from prayer because they do not confess that the Eucharist is the flesh of our Savior Jesus Christ, flesh which suffered for our sins and which that Father, in his goodness, raised up again. They who deny the gift of God are perishing in their disputes" (Letter to the Smyrnaeans 6:2–7:1).
Papias, [bishop of Hierapolis] who is now mentioned by us, affirms that he received the sayings of the apostles from those who accompanied them, and he, moreover, asserts that he heard in person Aristion and the presbyter John. Accordingly, he mentions them frequently by name, and in his writings gives their traditions [concerning Jesus]. . . . [There are] other passages of his in which he relates some miraculous deeds, stating that he acquired the knowledge of them from tradition." (fragment in Eusebius, Church History 3:39).
Septuagint part of OT Canon. Polycarp of Smyrna wrote with the idea that the book of Tobit was scripture:
When you can do good, defer it not, because ‘alms delivers from death’ [Tobit. 4:10, 12:9]. Be all of you subject to one another [1 Pet. 5:5], having your conduct blameless among the Gentiles [1 Pet. 2:12], and the Lord may not be blasphemed through you. But woe to him by whom the name of the Lord is blasphemed [Is. 52:5]!" (Letter to the Philadelphians 10).
At that time there flourished in the Church Hegesippus, whom we know from what has gone before, and Dionysius, bishop of Corinth, and another bishop, Pinytus of Crete, and besides these, Philip, and Apollinarius, and Melito, and Musanus, and Modestus, and, finally, Irenaeus. From them has come down to us in writing, the sound and orthodox faith received from tradition." (Eusebius of Caesarea, Church History 4:21).
Eucharist not symbolic
We call this food Eucharist, and no one else is permitted to partake of it, except one who believes our teaching to be true and who has been washed in the washing which is for the remission of sins and for regeneration [i.e., has received baptism] and is thereby living as Christ enjoined. For not as common bread nor common drink do we receive these; but since Jesus Christ our Savior was made incarnate by the word of God and had both flesh and blood for our salvation, so too, as we have been taught, the food which has been made into the Eucharist by the Eucharistic prayer set down by him, and by the change of which our blood and flesh is nurtured, is both the flesh and the blood of that incarnated Jesus" ( Justin Martyr, First Apology 66).
Mary, Full of Grace
[Jesus] became man by the Virgin so that the course which was taken by disobedience in the beginning through the agency of the serpent might be also the very course by which it would be put down. Eve, a virgin and undefiled, conceived the word of the serpent and bore disobedience and death. But the Virgin Mary received faith and joy when the angel Gabriel announced to her the glad tidings that the Spirit of the Lord would come upon her and the power of the Most High would overshadow her, for which reason the Holy One being born of her is the Son of God. And she replied ‘Be it done unto me according to your word’ [Luke 1:38]" (Justin Martyr, Dialogue with Trypho the Jew 100).
The veneration of relics is seen explicitly as early as the account of Polycarp’s martyrdom written by the Smyrnaeans in A.D. 156.
And after the exhibition, Tryphaena again received her [Thecla]. For her daughter Falconilla had died, and said to her in a dream: ‘Mother, you shall have this stranger Thecla in my place, in order that she may pray concerning me, and that I may be transferred to the place of the righteous’" (Acts of Paul and Thecla).
Montanus, declared a heretic by Asian councils, again showing a centralized church with authority.
Ireneaus talks about public confession (not explicit if it is before church or to priest alone.) (Against Heresies 1:22).
Referring to bishop of Rome, “Pope”
You [Pope Soter] have also, by your very admonition, brought together the planting that was made by Peter and Paul at Rome and at Corinth; for both of them alike planted in our Corinth and taught us; and both alike, teaching similarly in Italy, suffered martyrdom at the same time" (Dionysius of Corinth, Letter to Pope Soter, in Eusebius, History of the Church 2:25:8).