The Early Church Fathers on various topics: This was a 3700 hour project which included going through 22896 pages of the 38 volume set called Ante Nicene, Nicene, Post Nicene Fathers. I compiled 255 pages of quotes showing that the Early Church was always and completely Catholic. All of these quotes can be verified and found from the source which is free online.
Clement of Alexandria Who is the rich man that shall be saved ch42 [150-215]And that you may be still more confident, that repenting thus truly there remains for you a sure hope of salvation, listen to a tale? which is not a tale but a narrative, handed down and committed to the custody of memory, about the Apostle John...........I will give account to Christ for thee. If need be, I will willingly endure thy death, as the Lord did death for us. For thee I will surrender my life.
Tertullian On Repentance ch 7 [160-240 AD]
If the Lord's indulgence grants you the means of restoring what you had lost, be thankful for the benefit renewed, not to say amplified; for restoring is a greater thing than giving, inasmuch as having lost is more miserable than never having received at all.
Tertullian To His Wife ch 8 [160-240 AD]
The indulgences granted by the Lord are regulated by their own grace; the things which are objects of man's striving are attained by earnest pursuit...
Augustine of Hippo Enchiridion ch 66 [354-430 AD]
For many sins seem in this world to be overlooked and visited with no punishment, whose punishment is reserved for the future (for it is not in vain that the day when Christ shall come as Judge of quick and dead is peculiarly named the day of judgment); just as, on the other hand, many sins are punished in this life, which nevertheless are pardoned, and shall bring down no punishment in the future life. Accordingly, in reference to certain temporal punishments, which in this life are visited upon sinners, the apostle, addressing those whose sins are blotted out, and not reserved for the final judgment, says: "For if we would judge ourselves, we should not be judged. But when we are judged, we are chastened of the Lord, that we should not be condemned with the world."
Augustine of Hippo Enchiridion ch 70 [354-430 AD]
We must beware, however, lest any one should suppose that gross sins, such as are committed by those who shall not inherit the kingdom of God, may be daily perpetrated,and daily stoned for by almsgiving, The life must be changed for the better; and almsgiving must be used to propitiate God for past sins, not to purchase impunity for the commission of such sins in the future. For He has given no man license to sin, although in His mercy He may blot out sins that are already committed, if we do not neglect to make proper satisfaction.
4th Lateran Council (Ecumenical Council #12) ch 60 [1215-1216 AD]
From the complaints which have reached us from bishops in various parts of the world, we have come to know of serious and great excesses of certain abbots who, not content with the boundaries of their own authority, stretch out their hands to things belonging to the episcopal dignity : hearing matrimonial cases, enjoining public penances, even granting letters of indulgences and like presumptions...
4th Lateran Council (Ecumenical Council #12) ch 62 [1215-1216 AD]
Moreover, because the keys of the church are brought into contempt and satisfaction through penance loses its force through indiscriminate and excessive indulgences, which certain prelates of churches do not fear to grant, we therefore decree that when a basilica is dedicated, the indulgence shall not be for more than one year, whether it is dedicated by one bishop or by more than one, and for the anniversary of the dedication the remission of penances imposed is not to exceed forty days...