As far as churches as a group there is a vast difference as to the establishment of a church government organization. Catholic want to claim they started with Christ and Peter was the first pope.
The Baptist want to say they have always had a group who believed like Christ did. There is a group that believes that the Baptist churches actually existed in an unbroken chain since the time of Christ.
There is the perpetuity view which assumes that the Baptist faith and practices has existed since the time of Christ.
And as I said the successionist view or the Baptist successionism, which argues that Baptist churches actually existed in an unbroken chain since the time of Christ.
Personally I don’t agree with the “The Trail of Blood” a pamphlet by J.M. Carrol published in 1931. Some say Charles Surgeon held this view.
The name Baptist has not always existed of course. Has there always been a group of people who have held to the teaching of Christ? I would have to think that has happen, but not as a group or organization.
There have been groups that have disagreed with the Reformation and every other movement. One group was the Puritans and Separatists.
But if you are talking about “Baptist churches” you need to go back to 1609 in Amsterdam, with John Smyth as its pastor.
THERE IS LITTLE LIKENESS BETWEEN THE ORTHODOX CHRISTIAN OF THE EASTERN AND WESTERN CHURCHES. http://orthodoxwiki.org/Baptists (you can read this if you desire to.)
Baptists are a variety of Evangelical Protestantism. Baptists claim 90 million members worldwide, approximately seventy percent of which reside in the United States. It should be noted that Baptist members are those who have reached the "age of reason" and been baptized. Baptists do not count infants and young children as members. The primary theological differences between Baptists and Orthodox Christianity are the autonomy of each individual church, with no supervisory episcopal authority, a rejection of the sacramental nature of all seven Orthodox sacraments (Baptism, Chrismation, Confession, the Eucharist, Marriage, Holy Orders and Unction (and indeed, neither Chrismation nor Confession nor Unction are practiced by the Baptists even symbolically), and furthermore by their adherence to the heresy of "Believers Baptism", in which only adults are baptized, as a symbol, but in most Baptist conventions, also a prerequisite to partaking of the "Lord's Supper" (the also purely symbolic and non-Sacramental imitation of the Eucharist). These views will be expounded upon in the article.
Since there are at least sixty-five Baptist bodies with no structured ecclesiology, it's hard to precisely define their doctrines. Nevertheless, there are some points common to all Baptists. For example, most adherents place strong emphasis on the independence of the individual person ("individual soul liberty"), independence of each church, affirmation of believer's baptism, and distinctively American concepts such as freedom of religion and separation of church and state.
TODAY there are baptist that say they are the only church, within the Baptist group.
Independent Baptist are the true Baptist, and they are all in the World Baptist Fellowship which I 100% disagree with of course. And I was raised in the WBF.
To answer by question in the title of the post: Who are the true group of people in the church?
The true group of people who are Christians are those that God has called into His Kingdom the Elect. Those people are not in a group of churches, but rather a group of believers known as “the body of Christ”.
All those who have been saved by the grace of God and Jesus Christ are those who are in the same body. One Lord, One Body, One Lord.
I would like to think there has always been a group of believers that have followed the teaching of Christ. Any of Paul's churches he established could have been like that. But those churches were not a part of an organization. I don't think the seven churches of Asia Minor were part of the Catholic church. Some where along the timeline, all this organization started