Theology is not a subcategory of anthropology (or psychology).
The existence of God is clear from creation and conscience (despite those who repress this knowledge).
The law of God, written on our hearts, manifest in our conscience, reveals our true need for Christ.
Christ walked this earth and told us of this need, and then--wonder of wonders--met our need. He proved his identity with supernatural wonders including his own resurrection. That validates his message. The tomb is empty.
These are historical facts, not the byproducts of an immature father-hunger. They happened. "Under Pontius Pilate--it is all in order" as Lewis put it.