The ever-growing number of churches and diverse sects makes it difficult for some people to resolve the issue of which one of them is the true Church, and of whether the one and true Church exists at all in our times. Perhaps, some people think, the original apostolic Church gradually became splintered, and the currently-existing churches possess only fragments of its former spiritual wealth – grace and truth. Based upon such a view of the Church, some people believe that it can be reconstructed from existing Christian denominations by means of agreements and mutual compromises. This viewpoint lies at the base of the contemporary ecume- nical movement, which does not believe any one church to be the true Church. Perhaps, others think, the Church never had anything in common with official churches in principle, but always consisted of individual believers who belonged to various church groups. This last opinion has become embodied in the teaching that is being proposed by contemporary Protestant theologians about a so-called “invisible church.” And, finally, for many Christians it remains unclear whether the Church is needed at all, since man supposedly attains salvation through his faith.

All these contradictory and essentially false opinions of the Church originate from a misunderstanding of the central truth of Christ’s teaching on the salvation of man. When reading the Gospel and the apostolic epistles, it becomes obvious that the Saviour’s intention is to have men save their souls not singly and separately, but jointly, making up one grace-filled Kingdom of God. One should not forget that the kingdom of evil, headed by the prince of darkness, also acts unitedly in its battle against the Church.

Nevertheless, despite the variety of modern opinions about the Church, the majority of rational Christians agrees with the fact that the true Church of Christ existed in apostolic times as a group of people united in salvation. The Acts of the Apostles tell us of how the Church came into being in Jerusalem, when on the fiftieth day after the Lord’s Resurrection, the Holy Spirit descended upon the apostles in the form of fiery tongues. From that day the Christian faith quickly began to spread to all the corners of the far-flung Roman Empire.

As Christianity spread, Christian communities – churches began to appear in various towns and villages. In view of the great distances separating them, these communities lived their everyday life more-or-less isolated one from another. However, they regarded themselves as belonging to a single, united and apostolic Church. They were joined together by a single faith and a single source of grace, which was drawn from the holy sacraments (baptism, communion and the laying on of hands, i.e. ordination). At first these sacred actions were performed by the apostles themselves. However, soon the need arose for the apostles to have help, and so they chose worthy candidates from among the members of the Christian communities, whom they ordained as bishops, priests and deacons. The apostles imposed upon these bishops the responsibility of guarding the purity of Christian teaching, of teaching the faithful how to live piously, and of ordaining new bishops, priests and deacons. Thus, during the first several centuries, the Church continuously grew like a tree and spread throughout many countries, becoming enriched by spiritual experience, religious literature, church prayers and hymns, and later – by church architecture and iconography, but always retaining its essential nature of the true Church of Christ.

The Gospels and the apostolic epistles did not appear right away and not everywhere simultaneously. For many decades after the establishment of the Church, the source of instruction was not the Scriptures, but oral homilies, which the apostles themselves called “Tradition.” Holy Tradition is an apostolic source of instruction in faith. Within the Church it was always of decisive importance in determining what was considered to be correct and what was not. Whenever any issues arose that were at variance with apostolic tradition – be it in matters of faith, the performance of sacraments, or church administration – they were deemed to be false and were rejected. Continuing the apostolic tradition, the bishops of the first centuries of Christianity meticulously examined all Christian manuscripts, and gradually collected the writings of the apostles – the Gospels and the epistles – into a single set of book that were called the New Testament, and which, together with the books of the Old Testament, made up the Bible in its current form. This process of gathering the writings was finished in the 3rd century. Questionable books, though being passed off as apostolic writings, were not included in the Bible, but were called the Apocrypha. Now Christians of all denominations use the New Testament, often arbitrarily, irreverently, without realizing that it is the personal possession of the true Church, a treasure which it had so carefully amassed.

As a result of other testimonials that have come down to us, written by the disciples of the holy apostles, we know many precious details about the life and faith of Christian communities in the first centuries A.D. At that time the belief in the existence of a single, holy, apostolic Church was universal. Being faced with the fact of the existence of a real and single Church in the first centuries of Christianity, can we find a precise historic moment when it splintered and ceased to exist? An honest answer should be – no! The fact is that deviations from the purity of apostolic teaching – heresies – began to appear even in apostolic times. Especially active at that time were the Gnostic teachings, which mixed the Christian faith with elements of pagan philosophy. The apostles in their epistles warned the Christians against these teachings, and directly asserted that the followers of these sects had fallen away from the true faith. The apostles looked upon heretics as dry twigs that had broken off the church tree. Similarly the apostles’ successors, the bishops of the first centuries, did not accept as genuine the deviations from the apostolic faith which arose during their tenure, and excommunicated from the Church all persistent followers of such false teachings, in accordance with Apostle Paul’s instruction: “But though we, or an angel from heaven, preach any other gospel unto you than that which we have preached unto you, let him be accursed” (i.e. let him be excommunicated) (Gal. 1:8).

Thus, in the first centuries of Christianity, the issue of Church unity was clear: the Church was regarded as a single spiritual family, carrying on from apostolic times the true teaching, the true sacraments, and an unbroken succession of grace, passed on from bishop to bishop. The successors of the apostles had no doubts whatsoever that the Church was absolutely essential for salvation, because it preserves and passes on the pure teaching of Christ, it sanctifies the faithful and leads them to salvation. Using the imaginative similies of the Holy Scriptures, in the first centuries of Christianity the Church was seen as a sheltered sheep pen in which the Good Shepherd – Christ – protects His sheep from the “wolf” – the devil. The Church was compared to a Vine, from which its branches – the faithful – could draw the spiritual strength necessary for leading a Christian life and doing good deeds. The Church was understood to be the Body of Christ, in which each believer, as a member, performed a service needed for the entire organism. The Church was depicted as Noah’s ark, in which the faithful crossed the turbulent sea of life and reached the safe haven of the Heavenly Realm. The Church was compared to a high mountain that towered above human delusions and led its travelers towards heaven – to communion with God, the angels and the saints.

In the first centuries of Christianity, to believe in Christ meant to believe that the mission which He had accomplished on earth, and the means of salvation which He had given to the faithful, cannot be lost or snatched away by the efforts of the devil. The Old Testament prophets, the Lord Jesus Christ Himself, and His apostles specifically taught that the Church would remain until the end of existence. Similarly we, too, if we believe in Christ’s promise, must admit to the existence of His Church both in our time and to the end of the world. We have not yet indicated where it is to be found, but at present we are simply stating the situation in principle: the Church must exist somewhere in its holy, indivisible, real nature. A splintered, damaged, evaporated Church is not the real Church.

And so, where is it? What are the signs that would help us find it among the multitude of contemporary Christian branches?

First of all, the true Church must retain undefiled the purity of Christian teaching that was preached by the apostles. The purpose of the Son of God’s coming to earth was to bring truth to mankind, as He said before His suffering on the cross: “To this end was I born, and for this cause came I into the world, that I should bear witness unto the truth. Every one that is of the truth heareth my voice” (John 18:37). Apostle Paul, instructing his disciple Timothy on the performance of his bishop’s duties, concludes with the following words: “But if I tarry long, that thou mayest know how thou oughtest to behave thyself in the house of God, which is the church of the living God, the pillar and ground of the truth” (1 Timothy 3:15). It must be sorrowfully acknowledged that in the matter of teaching we see sharp disagreement among the contemporary branches of Christianity. In principle it is self-evident that those who differ cannot all be correct. If, for example, one church asserts that communion consists of the Body and Blood of Christ, while another denies it, it is impossible for both to be correct. Likewise, if one church believes in the real spiritual power of the sign of the cross, while another denies this power, then one of these churches is apparently in error. The true Church must be the one which in matters of faith does not differ in any way from the Church of the first centuries of Christianity. If we were to make an unbiased comparison of the teachings of contemporary Christian churches, we would have to conclude, as will be seen later, that only the Orthodox Church retains undamaged the faith of the ancient apostolic Church.

Another sign which may indicate to us the true Church is grace or the power of God, by which the Church is called upon to sanctify and fortify its faithful. Although grace is an invisible force, there is, however, an external condition by which one can determine its absence or presence, and that is – apostolic succession. From the time of the apostles grace was passed on to the faithful in the sacraments of baptism, communion, the laying on of hands (anointment and ordination), and others. These sacraments were first performed by the apostles, and later by bishops and priests. (Priests differed from bishops in that they did not have the right to perform the sacrament of ordination). The right to perform these sacraments was transferred exclusively by means of succession: the apostles ordained bishops and gave them the exclusive right to ordain other bishops, priests and deacons. The apostolic succession is like a holy flame, which from a single candle lights all the others. If the flame is extinguished and the chain of apostolic succession is broken, – there is no more priesthood or sacraments, and all the means of sanctifying the faithful are lost. For this reason, from apostolic times the apostolic succession was carefully watched: a bishop would be consecrated only by a true bishop, whose own consecration successively went back to the apostles. Those bishops who fell into heresy or led unworthy lives, were deposed and lost the right to perform sacraments or to ordain successors to themselves.

In our times there are only several churches whose apostolic succession is beyond doubt, – these are the Orthodox Church, the Catholic Church, and several non-Orthodox Eastern churches (that have fallen away, however, from the purity of apostolic teaching during the time of the Ecumenical Councils). Christian denominations which reject in principle the necessity of having a priesthood and observing apostolic succession, by that characteristic alone differ essentially from the Church of the first centuries and thus cannot be regarded as the true Church.

A spiritually sensitive person naturally has no need of external proofs of the grace of God when he experiences its warm and soothing effect, as it is transmitted to him in the sacraments and services of the Orthodox Church. (However, Christians must distinguish between the grace of God and that cheap and harmful ecstasy which sectarians, such as the Pentecostals, artificially arouse in themselves during their prayer meetings. The signs of true grace are inner peace, love of God and one’s fellow beings, modesty, humility, meekness, and similar characteristics, enumerated by Apostle Paul in his epistle to the Galatians.

Another sign of the true Church is its suffering. It may be difficult for people to determine which church is the true Church, but the devil – its enemy – has no such problems and knows it very well. He hates the Church and tries to destroy it. As we become acquainted with the history of the Church, we see that its history was truly written with the tears and the blood of martyrs for faith. Persecution was already begun by Jewish high priests and scribes in apostolic times. This was followed by three centuries of persecution in the Roman Empire by Roman emperors and rulers of the provinces. After that the Moslem Arabs took up the sword against the Church, followed by the Crusaders from the West. They so undermined the physical strength of Byzantium, that bastion of Orthodoxy, that it could not withstand the onslaught of the Turks in the 14th/15th centuries. And finally, the godless Communists surpassed all others with their cruelty, destroying more Christians than all the preceding persecutors. But behold the miracle: the blood of martyrs became the seed for new Christians, and the gates of hell cannot overcome the Church, just as Christ had promised.

Finally, a true and fairly easy method of finding the Church of Christ is historical investigation. The true Church must go back to apostolic times in unbroken succession. In order to apply the principle of historic investigation, there is no need to delve too deeply into all the details of the development and the propagation of Christianity. Suffice it to determine when one or the other church appeared. If it appeared, say, in the 16th or any other century besides apostolic times, it cannot be the true Church. By this characteristic alone we can exclude all the denominations claiming to be the true Church of Christ, which originate with Luther and his followers, such as Lutherans, Calvinists, Presbyterians, and later ones – Mormons, Baptists, Adventists, Jehovah’s witnesses, Pentecostals, and the like. These denominations have been founded not by Christ or His apostles, but by false prophets – various Luthers, Calvins, Henrys, Smiths, and other innovators.

Our goal is to acquaint the Orthodox reader with the history of the formation of the major branches of Christianity and with the essence of their teaching, in order to help the reader see how they differ from the one, holy and apostolic Church founded by Christ. During the theological arguments that took place from the 4th to the 8th centuries, several heretical groups fell away from the Church – Arians, Macedonians, Nestorians, Monophysites and Monophyletes (from whom evolved the modern-day Copts), iconoclasts and others. Their teachings were condemned by the Ecumenical Councils (of which there were seven), and since these heresies no longer represent a threat to Orthodox believers, we will not discuss them.

Let us begin with a few words about the Orthodox Church.