Proof?
The court is above its head on this one. The Concordat between Italy and the Vatican pretty well excludes the state from getting into such matters.
"All this granted, much remains. The contradictions [in the synopotc gospel accounts] are of minutae, not substance; in essentials the synoptic gospels agree remarkably well, and form a consistent portrait of Christ. In the enthusiasm of its discoveries the Higher Criticism has applied to the New Testament tests of authenticity so severe that by them a hundred ancient worthies - e.g., Hammurabi, David, Socrates - would fade into legend. Despite the prejudices and theological preconceptions of the evangelists, they record many incidents that mere inventors would have concealed - the competition of the apostles for high places in the Kingdom, their flight after Jesus' arrest, Peter's denial, the failure of Christ to work miracles in Galilee, the references of some auditors to his possible insanity, his early uncertainty of his mission, his confessions of ignorance as to the future, his moments of bitterness, his despairing cry on the cross; no one reading these scenes can doubt the reality of the figure behind them. That a few simple men should in one generation have invented so powerful and appealing a personality, so lofty an ethic and so inspiring a vision of human brotherhood, would be a miracle far more incredible than any recorded in the Gospels. After two centuries of Higher Criticism the outlines of the life, character, and teaching of Christ, remain remarkably clear, and constitute the most fascinating feature in the history of Western man.