What's the future of Catholic Church and Satan?

[Randy Carson]

from what i remember of history the catholic church came about after  the fall of the roman empire.  

In the West, xtianity was legitimized early in the 4th century and was made the official state religion later in the 4th century. 

Not exactly.

The Edict of Milan in AD 325 "legalized" Christianity in the sense that Christianity would be tolerated from that date forward (as Min rightly notes - but does not himself practice ).

However, the Catholic Church itself actually dates back to the apostles.

The early Church - the Church founded by Christ as promised in Matthew 16:18 - was that which was originally known as “the Way” (cf. Acts 24:14). Later, those individuals who followed Christ began to be called “Christians” beginning at Antioch (cf. Acts 11:26). As early as 107 A.D., those same individuals referred to themselves collectively as the “Catholic Church”. In a letter to the Church of Smyrna, Ignatius of Antioch wrote:

"You must all follow the bishop as Jesus Christ follows the Father, and the presbytery (priest) as you would the Apostles. Let no one do anything of concern to the Church without the bishop. Wherever the bishop appears, let the people be there; just as wherever Jesus Christ is, there is the Catholic Church." (Letter to the Smyrnaeans, A.D. 107, [8,1])

Notice that Ignatius does not take pains to introduce the term "Catholic Church"; instead he uses it in a manner suggesting that the name was already in use and familiar to his audience. This further suggests that the name, Catholic Church, had to have been coined much earlier in order to have achieved wide circulation by the time of this writing. In other words, the Christian assembly was calling itself the Catholic Church during the lifetime of the last Apostle, John, who died near the end of the first century. John, the beloved disciple, may have thought of himself as a member of the Catholic Church!

The Catholic Church began with Peter and the Apostles and continued without interruption or cessation through their disciples (Ignatius, Irenaeus, Polycarp, Clement, Justin Martyr, etc.) down to the present day. As a side note, it appears that the believers in Antioch may have coined both terms still in use today: “Christian” and “Catholic Church” – terms they used to describe the one body of believers in Christ.