Interesting thing i came across this week, was this verse about how to test or discern whether a spirit is of God or not. We test the spirits by asking one question: Did Jesus come in the flesh? Did He have a soul like us and a physical body like us? If a spirit says, no to this question, they are not of Him.
Interesting that this would be the one question scriptures teaches us to ask in order to discern spirits! It is a question of Jesus full incarnation into human form. I think that this question is the backdrop to the meaning of the resurrection. Because a purely “spirit” God, who did not come fully in the flesh, would have a different type of resurrection. Jesus, conversely, is the One who came as fully God and fully human, so He could fully resurrect, and fully enter us as humans and place us in His Resurrective stream!
This is the miracle of incarnation. And all our actual hope hinges on the fact that Jesus actually came as God, but took an entirely human form. He had a soul and body and a spirit in other words. This is basis for deliverance as well, in that what He has not entered cannot be delivered into and by and through Him. But He entered the whole, so He can deliver the whole. God is One, therefore, Jesus-being God-is also One and can enter the whole of a person or creature.
 He is One (integrated), and He came into the whole, so He can deliver the whole into His Kingdom, and integrate all the parts into one whole expression. He went to the place of death, He suffered as a human as God. He comes as the second Adam. The first Adam was made from earth; this one was made from both spirit and earth, so was able to offer another type of being to creation. Fully materially incarnate, and fully Eternal God. This makes Him another type of creation–the first fruits of a new creation. As we enter His Life we also become first fruits of a new type of creation. The first fruits, in Jewish culture, were always offered to God. So are we, in this stream of becoming first fruits offered to God. The first fruits of what–of an entire harvest, which is to come.
Ontologically, Jesus was fully God and fully human, so He is able to discern the whole, and deliver the whole into His Kingdom. Deliverance and discernment rest on this fact about Him. That His Spirit knows the whole of Reality-so can divide soul and spirit, and put them in proper relationship to one another.
And by this, we test (discern) the spirits!