Here's what I think about the Christian Faith based on what I read from the bible... Long before, there were already denominations or Lemans term "branches" of the Christian Faith, but their names were based on the places that they were in... this is clear on the Letters of Paul... He actually grouped them according to places and enumerated their focuses, their strengths and their weaknesses...
1 Corinthians 1
1Paul, called to be an apostle of Christ Jesus by the will of God, and our brother Sosthenes,
2To the church of God in Corinth, to those sanctified in Christ Jesus and called to be holy, together with all those everywhere who call on the name of our Lord Jesus Christ—their Lord and ours:
3Grace and peace to you from God our Father and the Lord Jesus Christ.
1 Thessalonians 1
1Paul, Silas[
a] and Timothy,
To the church of the Thessalonians in God the Father and the Lord Jesus Christ:
Grace and peace to you.[
b]
Which is kind of like what we have today... we have the Catholic Church which branches out to Roman Catholics, Eastern Orthodox Church, Independent Catholics, Liberal Catholics and Lutherans... same as the Born Again Christians which branched out Protestants to the Baptist, Adventist, Evangelical, Pentecostal and much more...
But we have to remember, where this all started... When Christ came down, showed us His love, died for your sins and rose in victory... as He rose to the heavens, that was also the birth of the Christian faith when He finally gave to the apostles the great commission to let the whole world know who Jesus is...
when you ask a Catholic if your a Christian or a Muslim, i think you know what your reply would be... you definitely say, I am a Christian, a member of the Catholic church, right?