The christology known to Antiochean sources especially is what I call "embodiment" christology. What this means is that Jesus was perceived as a full human being possessed by a spirit or angel from the womb. The important point is that he is a full human being, with his own psyche (=soul) and physical body. The spirit or angel is an extra something that he has from conception or quickening. Jesus functions as a container or vessel for the resident angel.
The rest of the Jerusalem paradigm survives intact. He still dies and is exalted to heaven where he is (re)-installed. As this great angel YHWH he will be revealed in the heavens, descending with a cry of command, the archangel's call. He will usher in God's kingdom after he destroys its enemies. He will sit in judgment. This tradition is carried on as late as the testimony of the Ebionites who taught that Christ was created like one of the archangels and was appointed by God to rule over the future age (Epiph., Pan. 30.16.2-4). This is also evidence that some of the Jerusalem sources were aware of this tradition, although it is impossible for me to tell if they picked it up after the paradigm was developed in Antioch, or were responsible for creating it in the first place and passing it on to Antioch.
What kind of soteriology is set into place when this christology is developed? Consider again the Jerusalem paradigm where Jesus' transformation into a glorified, divine being happened as the result of his righteous actions and piety, as a reward for upright behavior and obedience. It meant that anyone could imitate him and expect a similar reward - gradual transformation and eventual resurrection and divine body-status-immortality.
This soteriology could only work if Jesus was just like you and me. But what happened once he was an embodied angel from birth? A son of God from conception? Jesus didn't have to work for his divinity. He had already in the womb.
The road to salvation had no choice but to shift. It had to engage the power of the divine Jesus rather than the human Jesus. Redemption had to happen because of a divine action rather than a human action that could be imitated and repeated. This meant a fuller engagement with martyrological interpretations of Jesus' death which were already existing anyway. This is what Mark is about. So the efficacy of his death for sin atonement of sins of Israel was drawn out and universalized.
This doesn't mean that the behavioral soteriology from Jerusalem vanished or was replaced by the divine redemptive action. No. It survives and fuses with the sacrificial so that the sacrificial emerges dominant while the behavioral recedes into the background. It caused trouble though. Consider it. If a divine action redeemed the human being, then what was the benefit of good behavior? Paul has to face this trouble and he tries to explain it in Romans 12-13, where he says that good behavior is the outcome of a person's redemption and transformation, rather than the cause.
More on Paul in the next post in this very long series.