At some point in the future, I will turn these seven ideas into a series of essays or perhaps even a book. But for summary's sake, here is a brief description of these seven unique ideas (you can also see how they are linked in the chart above):
TRINITY: God is an eternal community of shared Love between the Father, Son, and Spirit, in infinite goodness, truth, and beauty.
AGAPE LOVE: Unconditional Love is the reason for our creation, why we are given freedom, and why God heals us when we misuse our freedom.
INCARNATION: To show us the depth of God's Love and heal us, God empties Godself and becomes human in the person of Jesus the Messiah.
SUBSTITUTION: In Jesus, God takes into Godself the full consequences of our sin, suffering, and death, by suffering with humans, for humans, as a human.
RESURRECTION: The Love of God is stronger than death, shown in Jesus' return from the grave, which guarantees the promise of our own resurrection.
SACRAMENT: The Holy Spirit shares Christ's life with us through tangible activities that continue the mission of the Incarnation in the world today.
ATONEMENT: God's ultimate desire is to make us at-one with God, through Jesus, in the Spirit, as we share fully in the eternal life of the Trinity.
After preaching the sermon, a close friend of mine noted that it is a "terrific summary of Christian theology", yet that "the individual items are not all unique, but the combination of the seven certainly is". This is a great observation that raises the question: Just how unique is the Christian worldview anyway? Are these concepts completely without parallel in other religions and worldviews?
I would agree that not all of the ideas presented today are conceptually original to Christianity. But the combination of all the concepts interlinked represents a free gift of considerable uniqueness to the world at large. And over time, after Christianity has spread, I would argue that various worldviews that see themselves as separate from Christianity-- from the rise of Islam to modern Hinduism(s) to Marxism to secular humanism-- have incorporated aspects of the Christian worldview into their spiritual and ethical systems (often without admitting it!).
But it's also fascinating to explore how religious ideas that PREDATE the rise of Christianity tend to be re-presented in a unique way in Classical Christian theology. I will start with the least original ideas (in my mind), and go to the most unique:
As CS Lewis and Tolkien have effectively noted: Various pagan mythologies have stories of dying and rising gods, gods that enter human form, virgin births, heroes that die for others, and heroes that go to the underworld to rescue someone. But also as Lewis and Tolkien note: It is a radical departure for a monotheistic religion to make such claims, unified in one person (rather than a series of heroes), and then to claim that person actually existed in history (as opposed to mythic time).
Agape and Buddhist compassion share significant overlap, as does the idea that we are created by the "free play" (lila) of God in Hinduism, and created by free agape in Christianity. And, of course, Agape draws strongly on the "khesed", or covenantally-faithful-loving-kindness of God in Judaism. I think there is some novelty in Christian theology saying not only that God DOES Love in action, but that God IS Love in essence.
Sacrament is common with many ancient religions. Most ancient religions seem to have a lively sense that the God(s) are at work through our rituals of worship and prayer. However, I do think sacrament has become novel again, since it seems that newer more de-mythologized and de-sacralized versions of religion- particularly Western Protestantism- often looses the sacramental idea (in my opinion).
Atonement (as I present it) implies both theosis (deification) and relational reconciliation. On their own, neither is unique. Judaism strongly emphasizes reconciliation. Various Hinduisms have nuanced versions of theosis. But I think Orthodox theology's fusion of both types of at-one-ment is fairly novel conceptually.
Substitution is, of course, all over the place in Temple-based Judaism and every other religion that has a sacrificial system. Some theory of substitution is at work in the idea that the innocent life dies on behalf of the "sinner". But those systems do not tend to make the vicarious sufferer the God Himself. It is usually one finite being offered for another finite being in the sight of the God(s).
Resurrection as a concept of course is directly from Judaism, via Zoroastrianism. It is actually a pretty unique concept when compared with living on as a disembodied "soul" in a heaven or a hell, or eternally being reincarnated in a cycle of Samsara, or simply ceasing to exist of being dissolved into the Source. What Christianity does with it that is unique is posit that a foretaste of resurrection has actually occurred in history to a specific person, which assures that resurrection will be a cosmic reality in the eschaton.
Which leads to Incarnation. I think this is actually pretty unique as claimed of Jesus of Nazareth by Classic Christian Theology. Hinduism has avatars, and Buddhism has bodhisattvas, which function in a kind of "bottom up" way, in which the individual human attains enlightenment/moksha, and comes into oneness with the divine essence or infinite nature that lies within their humanity. And in Ancient Paganism(s), finite gods enter human form temporarily, even in Virgin births. But the "top down" claim of Classic Christian Theology is that in Christ, the Infinite monotheistic God enters into human nature in a permanent way. I think that makes it conceptually unique and not directly drawn from a previous concept, especially since it arises out of a Jewish context that had little or no contact with Hinduism or Buddhism, and was antithetical to Paganism.
And, finally, the Trinity. Is this unique or not? In Hinduism, the infinite Brahman expresses itself in time as the cycle of Samsara, with Brahma (or the Divine Mother) as the Creator, Vishnu as the Preserver, and Shiva as the Destroyer/Transformer. And Vishnu frequently "incarnates" in human avatars such as Krishna and Rama (not unlike the Triune Son becoming Incarnate in Jesus, who is also said to be the "Logos" that preserves and upholds Creation). And is there not also a "trikaya" or threefold manifestation of Buddha nature in Buddhism? And does not Judaism itself also have a threefold understanding of the Divine as a transcendent YHWH, a creative Word or Wisdom that creates and upholds all things, and a Spirit or Shekinah glory the emanates the energies of God?
This is where I think it is helpful to use Karl Rahner's distinction between the "immanent Trinity" (God in Godself in eternal transcendence) and "economic Trinity" (God as God functions in history and time). All the models referred to above say that Ultimate Reality, in transcendence, beyond space and time, is simply indescribable. No predicates of any type can be assigned to the Eternal Brahman or Nirvana or Tao or YHWH. Thus, no threeness can be predicated of the transcendent Divine (or oneness, or being, or non-being, etc.). For other religions, The Ultimate may APPEAR as a kind of "Economic Trinity", but this is just because of the finite limitations of our ability to perceive. There is no "Immanent Trinity" to speak of, or not speak of, since the Ultimate is Nameless.
The Christian Trinity is unique in that it posits God as a Divine Community of Love in eternity, as an "Immanent Trinity". In Classic Christian Theology, the Trinity is not just another way to describe the economy of salvation (although it IS also that). It is ALSO a claim that Community and Love goes "all the way up", so to speak, into God's eternal nature. In an "Immanent Trinity", Oneness and Many-ness, Individuality and Community, Agape and Freedom, find a Ground of Being in the Eternal Nature of The Ultimate. They are not illusion or epiphenomena or lack of spiritual perception, but a finite reflection of the infinite Divine Trinity.
While these claims of "interconnected uniqueness" can and have been used as a ground for exclusion against other worldviews and religions, I would rather use them as a ground of hospitality and welcome. Yes, it is very possible to say "Because 'we' are unique, therefore 'they' are wrong and must be excluded". But it is also possible to say "We have something unique to offer them, I bet they have something unique to offer us, so let's talk".
It is also possible that the very things that Christians consider unique can also be a means by which they hallow what overlaps with other religions. Christians already-- or SHOULD already-- hallow the many Jewish contributions and antecedents that make Christianity possible, and so consider Judaism an older "sister religion". In a similar way, the shadows and hints of the Incarnation found in Pagan Mythology allowed early theologians to hallow these tales as a kind of "preparation for the Gospel".
Could not this kind of approach also bear fruit in contemporary engagement? Could Christians also see the various "Economic Trinities" of world religions as pointers to an "Immanent Trinity" of Divine Relationality? Could Christians also see avatars and bodhisattvas as pointers to the Incarnation? Could we not also learn more about Divine Agape from Buddhist concepts of compassion and Hindu concepts of lila?
I know there comes a danger of commodifying other religions as vehicles for Christianity in such an approach. And I would want a more broad ranging dialogue than just looking to other religions for concepts that can be "used" for Christianity. But I think that such a recognition of the commonalities and uniqueness of Christianity and other Religions is a far better approach that either a "exclusionary fundamentalism" on one side that says "we are right and they are wrong", and a "bland pluralism" on the other side that says "we are really all the same, and even where we're not the same it doesn't matter".
This is why I talked about these as "unique gifts" offered to the world at large. A gift is something that is offered without the expectation of return or reciprocation. Christianity offers these rich concepts as gifts to the world, to be a catalyst that helps humanity grow into its Divine vocation. If we deny an element of commonality and continuity with other religions, we become exclusionary. If we deny the uniqueness of these Christian concepts, then we have nothing left to give that everyone doesn't already have anyway, and lapse into mere toleration. If we hold both uniqueness and commonality hand in hand as we interact with others, we have a motive for genuine agape Love, as we give of our own identity for the good of the "other", whoever that "other" may be.