Eusebius' Ecclesiastical History
https://media2-production.mightynetworks.com/asset/57066268/Eusebius-b1.pdf
NOTES
AD 325
The name “Christian” indicates the very idea that a man, by the
knowledge and doctrine of Christ, is distinguished by modesty,
justice, patience, virtuous fortitude, and by a profession of piety
towards the one and only true God. This was all zealously practiced
by the ancient holy men, not just us. They did not, nor do we,
observe circumcision, the Sabbath, abstinence from certain foods,
nor any of the types and symbols Moses delivered because such
things as these do not belong to Christians.11 But they obviously
knew the Christ of God as He appeared to Abraham, communed
with Isaac, spoke to Jacob; and that He communed with Moses and
the prophets after him, has already been shown.
We should plainly see that the first and most ancient religion, that
of the holy men and Abraham, is the very religion lately announced
to all in the doctrines of Christ. Long before Abraham received the
command of circumcision, he received the testimony of
righteousness through faith; as the Word says,
Abraham believed in God, and it was counted unto him for
righteousness.
(Genesis 15:6)
Christ, the Word of God, revealed Himself to Abraham, who was
justified, yet not circumcised, and gave him a prophecy regarding
those who in coming Ages should be justified in the same way as
he was. The prophecy was in the following words:
And in you shall all the tribes of the earth be blessed.
(Genesis 12:3)
And again
To Abraham, a man of this character, it was said that all the nations
of the earth would be blessed in him. But the very religion of
Abraham has reappeared at the present time, practiced in deeds
more efficacious than words, by Christians alone throughout the
world. Everyone should be able to acknowledge that we Christians
practice one and the same lifestyle and have the same religion as
those ancient holy men. It is obvious that the perfect religion
committed to us by the teaching of Christ is not new and strange. It
is truly the original religion.
Everyone knows the names of the twelve Apostles of our Savior
from the Gospels, but there is no list of the seventy disciples.20 The
Barnabas who Paul wrote about in Galatians [2:1, 9, 13] and who is
mentioned in Acts was said to be one of the seventy. In Clement’s
fifth book of his Hypotyposes, he states that Sosthenes, who wrote
to the Corinthians [1 Corinthians 1:1] with Paul, was one of the
seventy as was Cephas, a man who had the same name as the
apostle Peter, and the one whom Paul says, “When Cephas came to
Antioch I withstood him to his face.21” [Galatians 2:11] Matthias,
also, who took the place of Judas, and the other one [Justus] who
was honored by being made a candidate with him [Acts 1:23], were
like-wise of the seventy. They say that Thaddeus also was one of
them, of whom I shall presently relate an account which has come
down to us.