But not all Christians "joined up". You're an idiot if you think that's true.
Baptists do not trace their heritage to the Protestant Reformation, but back to Jesus Christ and the Apostolic churches, as we see in the following overview by Curtis Whatley:
Though many Baptist groups sprang up during the Protestant Reformation, according to Colliers Encyclopedia, the Baptists have descended from some of the evangelical sects of the preceding age during which the Europe and suppressed all dissent.
A Catholic, Cardinal Hosius, President of the Council of Trent (1545-1563), wrote during the early years of the Reformation period, Were it not that the Baptists have been grievously tormented and cut off with the knife during the past twelve hundred years, they would swarm in greater numbers than all the reformers.
The Baptist Story
Gosh, according to Cardinal Hosius, they existed 1200 years before the reformation...which means they were around while the Roman Catholic church was developing.....
"John Clark Ridpath (1840-1900), a Methodist by denominational conviction, wrote, I should not readily admit that there was a Baptist church as far back as 100 A.D., although without doubt there were Baptist churches then, as all Christians were then Baptists.
The premise that first century Christians were Baptists runs counter to the Roman Catholic claim that the first church was Roman Catholic.
To this we need only point out that the first church was organized by Christ and His Apostles, and those Apostles became the nucleus of the church at Jerusalem, not Rome, and James was its leader, not Peter. We also contend that the bishop of Rome did not win primacy over other bishops until the 4th century, and that it wasnt until Gregory that the Roman bishop began to claim his supremacy over other bishops. Thus we see that Roman Catholicism dates back to the 4th Century at the earliest.