The Bible: A Biography, Karen Armstrong, c. 2007 -- Chapter 5

Charity.

Starts with the conversion of Constantine in 312 CE.

Armstrong doubts Christianity would have survived had it not been for Constantine's conversion.

apologiae: "rational explanations"

Evangelists relisted their pesher exegesis (p. 73), but the apologists found it more difficult.

Mentions Marcion. I can't find an earlier reference.

From wiki, Marcion:

Marcionism was an Early Christian dualist belief system that originated in the teachings of Marcion of Sinope at Rome around the year 144. Marcion believed Jesus was the savior sent by God, and Paul the Apostle was his chief apostle, but he rejected the Hebrew Bible and the God of Israel. Marcionists believed that the wrathful Hebrew God was a separate and lower entity than the all-forgiving God of the New Testament.

Ah, perhaps "Sinope."

Justin, 100 - 160: a pagan convert from Samaria in the Holy Land; eventually a martyr. He had been studying Greek philosophies, but found what he was looking for in Christianity. From Armstrong, p. 104:
Justin's notion of the Logos became central to the exegesis of the theologians who are know as the "fathers" of the church, because they created the seminal ideas of Christianity and adapted this Jewish faith to the Graeco-Roman world. From an early date, the fathers regarded the Tanakh as an elaborate sign system. As Irenaeus explained, the writings of Moses were really the words of Christ, the eternal Logos, who had been speaking through him. The fathers did not see the "Old Testament" as an anthology of writings but as a signle book with a unified message, which Irenaeus called it hypothesis, an argument "beneath" (hypo) the surface.

Jesus was the reason, purpose, and culmination of God's grand design.

The rise of the allegoria, p. 106.

Second to fifth century, Christianity growing; different schools.