what sort of redeemer is needed to bring us back to god?
Only one who is truly human and also truly God.
For to us a child is born, to us a son is given; and the government shall be upon his shoulder, and his name shall be called Wonderful Counselor, Mighty God, Everlasting Father, Prince of Peace.
Isaiah 9:6
Along with the offensive claim of exclusivity that Christianity carries - as Christ being the only way to salvation - there is also an offense heard as an apparent contradiction in Christian teaching. However, there is no such contradiction in any orthodox teaching - merely paradox.
The doctrine of the hypostatic union of Christ is one teaching that has left modern minds frustrated. This doctrine is stated in the Athanasian Creed as such:
He (Jesus) is God from the essence of the Father, begotten before time; and he is human from the essence of his mother, born in time; completely God, completely human, with a rational soul and human flesh; equal to the Father as regards divinity, less than the Father as regards humanity. Although he is God and human, yet Christ is not two, but one. He is one, however, not by his divinity being turned into flesh, but by God's taking humanity to himself. He is one, certainly not by the blending of his essence, but by the unity of his person. For just as one human is both rational soul and flesh, so too the one Christ is both God and human.
The hypostatic union teaches that Jesus Christ is both fully God and fully man, fully Creator and fully creature. He is not 50% God and 50% man, or 90% God and 10% man — or any other proportion that satisfies our mathematical proclivities. He is 100% God and 100% man. And this upsets and offends many, because something cannot be 200% itself by our logic with all its limitations! (The same mathematical frustrations occur in explanations of the Trinity). However, this is not a contradiction. A contradiction would be to say ‘he is 100% God and 100% not God’. That statement is contradictory, but the hypostatic union is not a contradiction - it is a paradox.
A paradox may have all the trappings of a contradiction. It goes against popular opinion and it seems to fly in the face of our own limited logic. However, paradoxical truths - truths that defy our understanding - exist even in the natural world. Ever since the quantum revolution of the early 20th Century, physicists have lived in the world of paradox (de Broglie’s Wave-Particle Duality of matter and light and Heisenberg’s Uncertainty Principle are just a few examples of this). Much about modern quantum theory initially lead rationalists to reject its claims, finding it offensive to their binary thinking (read about the history of the Schrodinger’s Cat illustration to gain a further appreciation as to how much these ideas were opposed). However, this theory has been confirmed time and time again, with experiment after experiment, and eventually quantum mechanics became the ‘orthodox interpretation’ of the physical universe viewed under a microscope, and is the basis of the Standard Model, the dominant theory employed today.
Some people think that the Grand Unified Theory will reconcile these paradoxes. However, it seems increasingly likely that is not the case at all. It seems like paradox exists for good in our natural sciences. Perhaps God wove these paradoxes into His creation, like a thread into a tapestry, to teach us something about His glorious nature.