While God is Spirit, we do not limit God to a spiritual state only. Prior to the incarnation we have numerous instances where God manifest in human form and interacted with men.
Now you have a spirit brother, so I would ask you, is your spirit separated from your physical aspect in regards to hunger, pain, et cetera? The truth is that it may be your very spirit which causes you to experience these. You may have in the past brought about pain in your life because of your spirit. When your body is wounded, for example, it can be equally true your spirit is as well. You get mad, punch a wall, break your hand, and then feel ashamed. The consequences do not separate the results to what impacts your spirit and what impacts you on a physical basis.
So too with God, going back to "the knowledge of good and evil," men became like God in that aspect. If we think God cannot grasp or understand a concept that is specific to humanity, then we have just reduced God to a lesser state than man himself.
It is because God understood man that He took upon Himself the form of man and died in his place, not the other way around.
God bless.