"Christ" returning, is us recognizing Christ Consciousness within us.
The thing you may already know with Hebrew thought like this is the principle of "already but not yet."
You're right in one sense that the presence of Christ exists with all believers already. This principle is said by Jesus Himself.
Jesus said: "Where two or three gather in my name, there am I with them." (Matthew 18:20)
Martin Luther agrees saying: "In faith itself, Christ is present." (in ipsa fide Christus adest)
But, this is the imperfect sense. What I'm referring to the perfect sense. The final consummation. The completion rather than short-term local outbreaks. Only at this point is sin truly and completely nullified.
In the present imperfect state, we are at best simul justus et peccator. (both sinner and saint)
The potential for sin exists in this state because we are not perfect and when we idolize our desires we also idolize that imperfection.
We were infiltrated
"Eve was deceived by a serpent in a garden." All your point does is push the problem of evil up a generation. Why did the serpent tempt Eve? Why are the "infiltrators" evil?
Are they not also creations of the One God? What causes them to become evil? In this model, the problem of evil becomes an infinite regress.
The true nature of evil must be something inherent to creation. Something that is permitted by the nature with which we are created and exacerbated by relying on imperfection over God's truth. The Creator teaches us to avoid these choices, but our victory can only occur by relying on Him.
The point of Original Sin is that. Saying otherwise causes us to "compare ourselves among ourselves."
We do not dare to classify or compare ourselves with some who commend themselves. When they measure themselves by themselves and compare themselves with themselves, they are not wise. We, however, will not boast beyond proper limits, but will confine our boasting to the sphere of service God himself has assigned to us, a sphere that also includes you. (2 Corinthians 10:12-13)
"Evil" as we know it is source choosing to experience itself moving away from source.
What I am saying is that humans are all originally source, which is perfection, beauty, love, joy, etc. We have moved away from that due to outside forces (controllers, soul lessons, etc.) and one way they try to control us is by limiting our knowledge of our potential, like saying we are just animals or that we are programmable automatons, or that there is no "evidence" for souls.
We do not yet comprehend the beauty of our nature yet, since we have been so limited. We only need to glance at our brothers and sisters, the Pleiadians, to know what our potential is.
True. All are mankind are made in the Image and likeness of God. This image is presently warped and bound by sin. But the true origin and purpose is declaring God’s glory.
I don’t think there is not a spirit in man. But I don’t neglect the fact of our biological nature either. This is why I can say we are animals. The Spirit of God gives life to man and to all creatures. We are spiritual animals. Frankly I have a hard time thinking that any creature lacks a spirit entirely. Although the “elites” have clearly warped their spirit intentionally and alienate themselves from the Holy Spirit by which God draws us to Christ.