Man’s relationship with Jesus Christ within context of Christian beliefs is a relationship many Christians do not have deep understanding of, as such just accept by faith. You may have been around such Christians who are convicted in their hearts, but have yet to arrive at full understanding of person of Jesus Christ. Seven years ago, it is not impossible I also would not have been able to proffer an evidence based answer to this post.
I agree with you that whenever God is entirely a conception of man’s mind, such conception never can be a true conception of grandness of God. I can understand then how you must have had to take a step back in what seemed to be the recognition that Jesus appears to be no more than man’s conception of God. I assure you, however, this seeming conception is a misconception. I will not merely proffer an opinion in this regard, rather I will establish using Christian Scriptures itself (the Bible) that Jesus Christ is not man’s conception of God.
Let me explain
First, let us establish that since God must abide in eternity, that is, is not bound by time, what we experience in say 4AD (the birth of Jesus Christ) already was God’s reality millions of years ago.
So then, when God says in Genesis Chapter 1,
“Let us make man in our own image”,
he is making man in image of Jesus Christ who already existed as image of God in eternity (Proverbs 8:22; 1Corinthians 1:24; John 8:58; Colossians 1:15). All of the verses I have listed establish eternity of existence of Jesus Christ beyond any reasonable doubt.
Since God intends for man to become brother or sister or mother to Jesus Christ (Matthew 12:50), man had to have the same sort of body, a less glorious one yes, but regardless the same structure of body and essence as Jesus Christ. It is the case then that the form we have is derived from the form of Jesus Christ, and not vice versa; this is a crucial point. Apart from form, just as Jesus is Spirit, Soul, and Body, so also we are spirit, soul, and body. Jesus was manifested in time for our sakes (our salvation) only. He already had existed in the form extended to us for millions of years before God decided to create man in image of Jesus Christ (Revelation 1:12–16; Revelation 22:12–13).
Jesus Christ was manifested to us about 4AD for sake of our salvation only. It was His form that was extended to us during Creation, not the case that He took our form in 4AD . In Jesus Christ, the form of a man always had existed in God’s presence (Ezekiel 1:10) for millions of years prior to Creation week.
Now, while Jesus is physical representation of God, as such is God (can the physical representation of God be anything other than God?), Jesus is God only because He is physical representation of an almighty God who is Spirit, incorporeal (your terminology), invincible (Colossians 1:15). So you see Jesus is not the Father (Jehovah), never claimed to be Jehovah, only claimed to be the one and only physical representation of God.
When Jesus tells Philip in John 14:9–10, “Anyone who has seen me has seen the Father”, he is declaring He alone is physical representation of Jehovah. This is the case because He simultaneously declares He is not the Father (verse 10).
If we ever see a physical representation of God, it is Jesus Christ we see because the almighty God is invincible, incorporeal. The God of the Bible, Jehovah, whom Jesus calls His Father never is conformed to our corporeal image.
So you see, we are like Jesus Christ not because the Bible seeks to conform God to our image, rather we are like Jesus Christ because if we are to develop relationship and fellowship with Jesus Christ — for whom is purpose of all of Creation (Colossians 1:16) — we must be made in His image.
Jehovah then experiences joy in the Bible not because we project what we are on Him; rather, we know joy because God experiences joy, and we are made in image of Jesus Christ, who in essence is God.
We have the form of Jesus Christ because true relationship is possible only when Like (Jesus Christ) relates with like (man, woman).