so HOW did Christianity spread in the beginning?

Adolph von Harnack is widely considered to be one of the greatest Church Historians of all time. Here are his conclusions as to what the "most important" factors were in the spread of Christianity in the 2nd and 3rd centuries. He writes:

"In its missionary activities, the Christian religion presented itself as something more than the gospel of redemption and of ministering love; it was also the religion of the Spirit and of power. No doubt, it verified its character as Spirit and power by the very fact that it brought redemption and succor to mankind, freeing them from demons (see above, pp. 125 f.) and from the misery of life. But the witness of the Spirit had a wider reach than even this. “I came to you in weakness and fear and with great trembling; nor were my speech and preach­ing in persuasive words of wisdom but in demonstration of the Spirit and of power" (1 Cor. ii. 3, 4). Though Paul in these words is certainly thinking of his conflict with demons and of their palpable defeat, he is by no means thinking of that alone, but also of all the wonderful deeds that accompanied the labors of the apostles and the founding of the church. These were not confined to his own person. From all directions they were reported, in connection with other missionaries as well...

The variety of expressions here is in itself a proof of the number of phenomena, which emerge in this connection. Let us try to single out the most important of them.

(1) God speaks to the missionaries in visions, dreams, a ecstasy, revealing to them affairs of moment and also trifles, controlling their plans, pointing out the roads on which they are to travel, the cities where they are to stay, and the persons whom they are to visit. Visions occur especially after a martyr­dom...

(2) At the missionary addresses of the apostles or evangelist, or at the services of the churches which they founded, sudden movements of rapture are experienced, many of them being simultaneous seizures; these are either full of terror and dismay, convulsing the whole spiritual life, or exultant outbursts of a joy that sees heaven opened to its eyes...

(3) Some are inspired who have power to clothe their experi­ence in words-prophets to explain the past, to interpret and to fathom the present, and to foretell the future. Their prophecies relate to the general course of history, but also to the fortunes of individuals, to what individuals are to do or leave undone.

(4) Brethren are inspired with the impulse to improvise prayers and hymns and psalms.

(5) Others are so filled with the Spirit that they lose con­sciousness and break out in stammering speech and cries, or in unintelligible utterances-which can be interpreted, however, by those who have the gift.

(6) Into the hands of others, again, the Spirit slips a pen, either in an ecstasy or in exalted moments of spiritual tension; they not merely speak but write as they are bidden.

(7) Sick persons are brought and healed by the missionaries, or by brethren who have been but recently awakened; wild paroxysms of terror before God's presence are also soothed, and in the name of Jesus demons are cast out.

(8) The Spirit impels men to an immense variety of extra­ordinary actions-to symbolic actions which are meant to reveal some mystery or to give some directions for life, as well as to deeds of heroism.

(9) Some perceive the presence of the Spirit with every sense; they see its brilliant light, they hear its voice, they smell the fragrance of immortality and taste its sweetness. Nay more; they see celestial persons with their own eyes, see them and also hear them; they peer into what is hidden or distant or to come; they are even rapt into the world to come, into heaven itself, where they listen to “words that cannot be uttered." 

(10) But although the Spirit manifests itself through marvels like these, it is no less effective in heightening the religious and the moral powers, which operate with such purity and power in certain individuals that they bear palpably the stamp of their divine origin..."(251-2, The Mission and Expansion of Christianity in the First Three Centuries).  

Harnack was not a Charismatic. He wasn't even an evangelical. He was a liberal German Lutheran theologian that approached Church History as objectively as possible and these were his remarkable conclusions.

These are the very same conclusions that we are witnessing today. It is powerful manifestations of the Holy Spirit, through prophecies, healings, visions and dreams, exorcisms, trances and/or other supernatural encounters or experiences that are bringing muslims, hindus and followers of other false religions to Christ. In this blog we have recorded literally hundreds of examples that corroborate Harnack's conclusions.