Why be good?

[Jenny A]

You did notice that what little we know of Ignatious is his own writings addressing heresy?  If it was all one big happy united church, who were these heretics?  Ignatious, is not proof of a united church, rather the reverse, he's proof there were Christians who believed rather differently, including in particular the Gnostics and the Docetists. 

Gee, I don't think there has been any attempt to claim anything else.

There were lots of heretical movements in the earliest days, and little by little, the Church worked through each of the theological disputes involved and established what was orthodox. This is where the creeds came from.

Now, you might argue: See? There were LOTS of "churches" but the Catholic Church simply won the battle. Well, yeah, it did, but winning is not the only consideration. Catholicism "won" because its theology was better and because it was apostolic in origin and because Jesus promised to build it.  Apostolic succession is an important factor.

Yes, that is exactly what I do say.  And I would add, that what came out of Rome mostly won, for the simple reason that Rome held the purse strings.  Rome funded small outlying Christian communities and funded missionaries.  It's no surprise that it's ideas became dominant.   Compare Paul's other letters to his letter to the Romans.  In that letter Paul is asking for support and he's willing to modify his views, or at least soft peddle them.  As went Paul, so went many others.  

But consider what these three Early Church Fathers had to say about the clear distinction between the Catholic Church and the heretics:

Cyril of Jerusalem

[The Church] is called Catholic, then, because it extends over the whole world, from end to end of the earth, and because it teaches universally and infallibly each and every doctrine which must come to the knowledge of men, concerning things visible and invisible, heavenly and earthly, and because it brings every race of men into subjection to godliness” (Catechetical Lectures 18:23, [A.D. 350]).

 
"And if you ever are visiting in cities, do not inquire simply where the house of the Lord is - for the others, sects of impious, attempt to call their dens 'houses of the Lord' - nor ask merely where the Church is, but where is the Catholic Church, for this is the name peculiar to this holy Church, the Mother of us all, which is the Spouse of our Lord Jesus Christ, the only begotten Son of God." (Cathechetical Lectures 18:26, [A.D. 350])
 
Athanasius
 
"Let us note that the very tradition, teaching, and faith of the Catholic Church from the beginning, which the Lord gave, was preached by the Apostles, and was preserved by the Fathers. On this was the Church founded; and if anyone departs from this, he neither is nor any longer ought to be called a Christian." (St. Athanasius, "Four Letters to Serapion of Thmuisc," [c.AD  360].
 
Augustine

“We must hold to the Christian religion and to communication in her Church, which is Catholic and which is called Catholic not only by her own members but even by all her enemies. When heretics or the adherents of schisms talk about her, not among themselves but with strangers, willy-nilly they call her nothing else but Catholic. They will not be understood unless they distinguish her by this name, which the whole world employs in her regard.” (The True Religion 7:12, [A.D. 390]).

"[T]he very name of Catholic . . . belongs to this Church alone . . . so much so that, although all heretics want to be called ‘catholic,' when a stranger inquires where the Catholic Church meets, none of the heretics would dare to point out his own basilica or house" (Against the Letter of Mani Called `The Foundation' 4:5 [AD 397]).

Yep, spoken like anyone trying to win a doctrinal war.  Don't listen to them, listen to us.  We are the largest group, and we took upon ourselves the winning name.  So?