Theophilus was a native of Maldive Islands, off Kerala coast. Emperor Constantine took him as a hostage so that the Maldive people will not plunder Roman ships as it passed that way. In Rome he became a Christian and became a Bishop. He visited India and noted that their worship practices differed considerably from those of other parts of the world. Particularly he noticed that Indians sang, heard the gospel and worshipped sitting down (which is the Hindu tradition) he thought they were outrageous and ordered it changed. Probably the practice of worship standing was introduced from that time onwards.

It may be assumed that Indians sent their priests for training and studies to Syria. There was one Daniel who translated the commentary on the Epistle to the Romans from Greek to Syriac in Edessa. He signed it as Daniel, the priest, the Indian. Ecclesiastical language of India was probably Greek and Syriac as the teaching of Bible came from there. Greek inscriptions are found on the bells of several churches. Until very recently the liturgy was mainly in Syriac. We maintain the flavor of this liturgy even today by retaining several Syriac phrases like Amen, Kurialaison, Brak-mar-Scoumenkalos et. and several Syrian chants.

Around AD 522, Cosmos a rich Christian merchant from Alexandria, visited India and wrote a book called Universal Christian Topology. He describes his visit thus:

"We have found the church not destroyed, but very widely diffused and the whole world filled with the doctrine of Christ, which is being day by day propagated and the Gospel preached over the whole earth. This I have seen with my own eyes in many places and have heard narrated by others. I as a witness of truth relate: In the land of Taprobane (Srilanka), Inner India, where the Indian sea is, there is a church of Christians, with clergy and congregation of believers, though I know not if there be any Christians further in this direction. And such also is the case in the land called Male (Malabar), where the pepper grows. And in the place called Kallia (Kollam) there is a bishop appointed from Persia, as well as in the island called Dioscores (Socotra) in the same Indian Sea. The inhabitants of that island speak Greek, having been originally settled there by Ptolemies, who ruled after Alexander of Macedonia. There are clergy there also ordained and sent from Persia to minister among the people of the island, and the multitude of Christians...."

Soon after the formation of the Church Heresy and variations in teachings were in existence in one form or other. During the Apostolic Period, they were settled with the mediation of the Apostles and Apostolic Synods and councils. The first of the council was the council of Jerusalem where the question of gentile inclusion in the church. However after the apostolic period this continued. Even today we have large number of theological systems varying ever so slightly. These movements arose powerfully around 400 A.D when Christianity became free from oppression and being a Christian became a prestige. In the year AD 425 Nestorius, a presbyter of the Church of Antioch became the Partriarch of Constantinople. He legitimately objected to the epithet of "Theokotos" "Mother of God" as applied to Mary since Mary was only the mother of the incarnation and not the mother who produced a God. This would imply that Mary was a Goddess. (We can now see how this epithet has led to the Marialotary and all the attempts to make Mary coredemptrix and equal in status with the trinity). In this sense he was indeed right. However he was understood to have propounded the concept that the Logos of God indwelt Jesus the man. Thus there were two natures in Jesus at the same time. If we are to judge by the Nestorian churches of today this was a misunderstanding.

Cyril the Patriarch of Alexandria opposed this dual nature concept and insisted on the unity that Jesus was perfect man and perfect God without inconsistency. The controversy reached a climax when these Patriarchs excommunicated each other. However the conduct of the Ephesus council was totally deplorable that Nestorius was not ever given a hearing. By the time Nestorius arrived at Ephesus the council had voted against him and he was excommunicated and exiled. Its decision though universally accepted, the way the issue was treated is still considered deplorable. The Nestorius a genius theologian of the time was derided without even giving him a hearing. Nestorius certainly foresaw the consequence of the epithet Theokotos.

The fight went on and in AD 451 the Nestorians claimed a victory in the council of Chaldeons in the year 451. In this council it was declared that in Christ the two natures were hypostatically united, without mixture, confusion and divisibility.

Cyril the Patriarch of Alexandria and John the Patriarch of Antioch finally reconciled. Nestorians adopted the name Chaldeon Church and the Patriarch took the title of Patriarch of Babylon.

These infights in the Middle East and Europe had its repercussions in India too. There exists a Chaldean church with few followings even today, though majority of the Christian churches remained faithful to the declarations of Nicea and Ephesus.

By this period, the great Empire of the Chera Kingdom came to ruins and an immense number of small independent Kingdoms came into existence. Their extents were limited. Thus the areas where Christians were in prominence established themselves into Kingdoms. Christians were traditionally good statesmen and warriors. Though there might have been several such centers of strong hold of Christians in Kerala, one particular Villarvattom Kingdom is mentioned often. This Kingdom Villarvattom Pana extended from the coastal islands of Chennamangalam, Maliankara and others to the north of and south of Udayamperoor. The capital of this kingdom was at mahadevarpattanam in the island of Chennamangalam and later it was shifted to Udayamperoor when the Arab invaders attached the island. The Udayamperror Church, which stands even today was built by Raja of Villarvottam in A.D 510. There are several inscriptions in this church that supports this including the mention of one Raja Thomas who ruled in AD 900. Pope John XXII in his letter sent with Friar Jordan address himself to the successor of Raja Thomas in A.D 1330 Later in A.D 43 Pope Eugene IV addresses to Raja Thomas in A.D 1439. The papal record mentions "that there is a Kingdom twenty days journey from Cathay, of which the king and all the inhabitants are Christians, but heretics, being said to be Nestorians." "Historia de Variatate Fortunae, liv. IV, Poggi Bracciolini , Secretary to Pope Eugenius IV) Though there are several traditions in this regards, no details or documentation apart from scattered references and archaeological artifacts can be found.