Material available from the Church Fathers of the apostolic era say that their church was Catholic.
They believed in One,Visible and Catholic Church.
They believed in 'The Real Presence' of the flesh & blood of the Lord, in the Eucharist.
They believed in the Primacy of the Church in Rome, Peter & the Pope
They believed in Apostolic Succession.
They practiced Infant Baptism
They practiced the sacrament of Confession before a priest
They had Priests to administer the services.
They believed Mary was the Mother of God, and the Marian dogmas, she was Ever Virgin, etc
They prayed to saints
They prayed for the dead.
They believed in Purgatory.
They practiced only what the Catholic Church preached then and the same that is practiced now by the One Catholic Church.
The "The Church is Catholic, Visible, ONE and uncorruptible"
Ignatius of Antioch (AD 110)
your bishop, every one of you, as obediently as Jesus Christ followed the Father. Obey
your clergy too as you would the apostles; give your deacons the same reverence that you would to a command of God. Make sure that no step affecting the Church is ever taken by anyone without the bishop’s
sanction. The sole Eucharist you should consider valid is one that is celebrated
by the bishop himself, or by some person authorized by him. Where the bishop is to be seen, there let all his people be; just as, wherever Jesus Christ is present, there is
the Catholic Church (Letter to the Smyrneans 8:2 [A.D. 110]).
In like manner let everyone respect the deacons as they would respect Jesus Christ, and just as they respect the bishop as a type of the Father,
and the presbyters as the council of God and college of the apostles. Without these,
it cannot be called a Church. I am confident that you accept this, for I have received the exemplar of your love and have
it with me in the person of your bishop. His very demeanor is a great lesson and his meekness is his strength. I believe that even the godless do respect him (Letter to the Trallians 3:1-2 [A. D. 110]).
The Martyrdom of Polycarp (AD 110)
When finally he concluded
his prayer, after remembering all who had at any time come his way – small folk and great folk, distinguished and undistinguished,
and the whole Catholic Church throughout the world – the time for departure
came. So they placed him on an ass, and brought him into the city on a great Sabbath (The Martyrdom of Polycarp 8 [A.D. 110]).
Irenaeus (AD 189)
The Catholic Church
possesses one and the same faith throughout the whole world, as we have already said (Against Heresies 1:10 [A.D. 189]).
therefore we have such proofs, it is not necessary to seek the truth among others
which it is easy to obtain from the Church; since the apostles, like a rich man
[depositing his money] in a bank, lodged in her hands most copiously all things pertaining to the truth: so that every man,
whosoever will, can draw from her the water of life. For she is the entrance to
life; all others are
thieves and robbers. On this account we are bound to avoid them, but to make choice of the things pertaining
to the Church with the utmost diligence, and to lay hold of the tradition of the truth. For how stands the case? Suppose there should arise a dispute relative to some important question among us. Should we not have recourse to
the most ancient churches with which the apostles held constant intercourse, and learn from them what is certain and clear
in regard to the present question? For how should it be if the apostles themselves had not left us writings? Would it not be necessary
[in that case] to follow the course of the tradition which they handed down to those to whom they did commit the churches? (ibid. 3:4).
Tertullian (AD 200)
was Marcion then, that shipmaster of Pontus, the zealous student of Stoicism? Where was Valentinus then, the disciple of Platonism?
For it is evident that those men lived not so long ago – in the reign of Antoninus for the most part – and that
they at first were believers in the doctrine of the Catholic Church, in the church
of Rome under the episcopate of the blessed Eleutherus, until on account of their ever restless curiosity, with which
they even infected the brethren, they were more than once expelled (On the Prescription Against Heretics 22,30 [A.D.200])
(AD 251, 253, 256)
"The spouse of Christ cannot be adulterous; she is uncorrupted and pure. She knows one home;
she guards with chaste modesty the sanctity of one couch. She keeps us for God. She appoints the sons whom she has born for
the kingdom. Whoever is separated from the Church and is joined to an adulteress, is separated from the promises of the Church;
nor can he who forsakes the Church of Christ attain to the rewards of Christ. He is a stranger; he is profane; he is an enemy.
He can no longer have God for his Father, who has not the Church for his mother. If any one could escape who was outside the
ark of Noah, then he also may escape who shall be outside of the Church. The Lord warns, saying, 'He who is not with me is
against me, and he who gathereth not with me scattereth.' Cyprian, On Unity, 6 (A.D.
Peter speaks there, on whom the Church was to be built, teaching and showing in the name of the Church, that although a rebellious and arrogant multitude of those who will not hear or obey may depart, yet the Church does not depart
from Christ; and they are the Church who are a people united to the priest, and the
flock which adheres to its pastor. Whence you ought to know that the bishop is in the Church, and the Church in the bishop;
and if any one be not with the bishop, that he is not in the Church, and that those flatter themselves in vain who creep in,
not having peace with God’s priests, and think that they communicate secretly with some; while the Church which is Catholic and one, is not cut nor divided, but is indeed connected and
bound together by the cement of priests who cohere with one another
(Letters 66 [A.D. 253]).
"Separate a ray of the sun from its body of light, its unity does not allow a division of
light; break a branch from a tree,--when broken, it will not be able to bud; cut off the stream from its fountain, and that
which is cut off dries up. Thus also the Church, shone over with the light of the Lord, sheds forth her rays over the whole
world, yet it is one light which is everywhere diffused, nor is the unity of the body separated. Her fruitful abundance spreads
her branches over the whole world. She broadly expands her rivers, liberally flowing, yet her head is one, her source one;
and she is one mother, plentiful in the results of fruitfulness: from her womb we are born, by her milk we are nourished,
by her spirit we are animated." Cyprian, Unity of the Church, 5 (A.D. 256).
Sola Fide said of the Catholic Church