Since the birth of the church there has always and will always be a single church. In Matthew 16:18 Jesus said, "And I say also unto thee, That thou art Peter, and upon this rock I will build my church; and the gates of hell shall not prevail against it."
Jesus has only built one church, the Christian church. The church that is modeled after that of Christ. Its foundation can be found in Ephesians 2:19-22: "Now therefore ye are no more strangers and foreigners, but fellow citizens with the saints, and of the household of God; In whom ye also are builded together for an habitation of God through the Spirit. In whom all the building fitly framed together groweth unto an holy temple in the Lord: And are built upon the foundation of the apostles and prophets, Jesus Christ himself being the chief corner stone;"
Did you notice the singularity in these verses? "The household of God", "for a habitation of God", "the building", "a holy temple", and "Christ being the chief corner stone." The Christian church is intended to be a singular body of believers who hold the Bible as the written inspired truth of God's divine instruction and revelation. There is no other source that is written from which the church draws its directives. The Bible is complete and needs no addition, retraction, or substitution. What church is the true church? The Apostolic church? The Catholic church? The Baptist church? The Lutheran church? The Non-denominational church? Are they all THE church or none? Christianity has been highjacked by denominationalism! Due to doctrinal division we have multiple denominations that believe, teach, and live differently. That is not the singular, unified church that Christ established. We are bond, and marginalized, by these divisions. As individuals we must come to the realization that we are hindering the work of Christ, and will not see the impact that we can have on the world. Herein lies the problem, as individuals, we identify with our denominal affiliation rather than the Word of God! I recently delivered a message to the church entitled, "I'm Not A Denomination, I Am A Disciple! I want to be a student of the Word of God. What makes a person a specific denomination is that they are identifying with its prescribed doctrinal beliefs and traditions! What makes a person a Christian is that they identify with Christ through their faith and obedience to His word. We need to take back the faith. Here is how it begins...we need to let go the denominational affiliations that we so strongly identify with, and begin to search the scriptures. If our church's teaching doesn't align with the Word of God, we need to start asking questions. A great detriment to our faith is the high percentage of believers who are actually ignorant of what the Bible says. The Apostle Paul instructed Timothy to, "study to show thyself approved unto God a workman that needeth not to be ashamed, rightly dividing the word of truth!" The second step in taking back our faith is to heed the first step. We will all contend that what we believe is the truth and everyone else is in error. This thinking results in denominationalism, rather than unadulterated Christianity! We can do our faith a favor by assuming we may be in error, opening our Bibles, and comparing our teachings and traditions with what we find there.
Allow me to be transparent. I do NOT believe that there is a single denomination or organization that holds the rights to the Christian church. The Church belongs to Christ and is made up of those who identify with Him through His word. I believe that there are Christians in every denomination, but not every denomination is reflective of the church that Christ intends us to be.