From covenant to cosmos

By the first century CE, the theology of one God had been shaped by centuries of crisis, reform, and reinterpretation. Judaism had moved from the local cult of Yahweh to an abstract, universal monotheism anchored in Scripture and ethics. Yet within the pluralistic world of the Roman Empire, new questions arose: Could the one God reveal himself in human history? Could divine unity embrace diversity, word, spirit, incarnation, without collapsing into polytheism?

Early Christianity arose as a Jewish answer to those questions, not as a rejection of Judaism but as its radical extension.

The crucified Messiah and divine paradox

The conviction that Jesus of Nazareth had been raised from the dead transformed Jewish messianic expectation into a new theology of divine presence. Where Judaism had preserved God’s transcendence, early Christians proclaimed that the one God had acted within history through his “Messiah.” This was not yet metaphysical speculation but the reinterpretation of monotheism in narrative form: God’s sovereignty manifested through suffering and reversal.1

The earliest Christian confessions (“Jesus is Lord,” Kyrios Iēsous) adapted the Septuagint’s divine title Kyrios for Yahweh.2 By applying it to Jesus, believers were not inventing a second god but including him within the identity of the one God. This hermeneutical expansion, using Jewish Scripture’s language for a new historical experience, was the seed of later Christology.

The Logos and Hellenistic synthesis

As the faith spread through the Greek-speaking world, thinkers sought to express revelation in the terms of philosophical monotheism. The Gospel of John opens: “In the beginning was the Logos, and the Logos was with God, and the Logos was God.” Here the Greek Logos (Word, Reason) bridges Israelite and Hellenistic cosmologies: it is at once the creative speech of Genesis and the rational principle of Stoic and Platonic thought.3

Philo of Alexandria had already spoken of the Logos as the intermediary between God and cosmos, the “image of God.”4 John’s innovation was to identify that Logos with a historical person: “The Word became flesh.” Christianity thus translated Jewish revelation into philosophical universalism: divine wisdom incarnate for all humanity.

Paul and the universal covenant

For Paul of Tarsus, a diaspora Jew steeped in Greek language and Pharisaic law, the resurrection revealed that the covenant’s promises now extended beyond Israel. He argued that faith, not ethnicity or ritual law, defined membership in God’s people, fulfilling Abraham’s blessing to “all nations.” This was not a break with monotheism but its ethical globalization: one God creating one humanity.5

Paul’s theology reframed the Shema (Deut. 6:4):

“For us there is one God, the Father, from whom are all things, and one Lord, Jesus Christ, through whom are all things” (1 Cor. 8:6).
Here the single divine identity is expressed in relational terms, source and mediator, not rivals. In doing so, Paul articulated the first binitarian monotheism: diversity within unity, rooted in Scripture.

Spirit and community

As early communities spread across the Mediterranean, they experienced divine power through what they called the Holy Spirit, an idea drawn from the Hebrew ruaḥ, God’s breath of life. The Spirit was understood as the continuing presence of God in the world, inspiring prophecy and binding believers into a single body. This concept completed a triadic pattern already implicit in Jewish texts (Word, Wisdom, Spirit) and prepared the ground for later Trinitarian theology.6 The triad was not yet a metaphysical doctrine; it was experiential, the believers’ way of naming how the one God acted in creation, redemption, and inspiration.

6. The problem of identity

For Jews who did not accept Jesus as Messiah, the Christian claim seemed paradoxical or blasphemous: how could the indivisible God appear in human form? For pagans, it appeared philosophical: a bridge between the high God of Plato and the living world of matter. The early Church’s task was to express unity and plurality without contradiction, hence the later debates about the Trinity and Christ’s nature.

In the second and third centuries, theologians such as Justin Martyr, Irenaeus, and Origen drew explicitly on Platonic and Stoic categories to articulate how the Logos could be both distinct and divine.7 Their formulations remained anchored in Jewish monotheism but clothed in Greek metaphysics.

Continuity and transformation

Early Christianity did not abandon Jewish monotheism; it universalized it.

• From Israel’s covenant it inherited ethical monotheism: one God demanding righteousness.

• From Hellenism it borrowed the vocabulary of reason and being.

• From the experience of Jesus and the Spirit it derived a new grammar of divine presence.

The result was a faith that could speak simultaneously to Jewish expectation and Greek philosophy, a religion of revelation and reason, historical and cosmic. In this synthesis lay Christianity’s enduring appeal: it offered the one God of Israel to the world, but in a form the world could recognize.

• 1. N. T. Wright, The Resurrection of the Son of God (Minneapolis: Fortress, 2003), 709–714.
• 2. Larry W. Hurtado, Lord Jesus Christ: Devotion to Jesus in Earliest Christianity (Grand Rapids: Eerdmans, 2003), 99–106.
• 3. C. H. Dodd, The Interpretation of the Fourth Gospel (Cambridge: CUP, 1953), 263–276.
• 4. Philo, On the Creation, §§18–25; On Dreams, 1.215–219.
• 5. Paula Fredriksen, Paul: The Pagans’ Apostle (New Haven: Yale University Press, 2017), 58–67.
• 6. James D. G. Dunn, The Theology of Paul the Apostle (Grand Rapids: Eerdmans, 1998), 261–268.
• 7. Jaroslav Pelikan, The Christian Tradition, Vol. 1: The Emergence of the Catholic Tradition (100–600) (Chicago: University of Chicago Press, 1971), 173–186.