On page 30 of "Jesus of Nazareth", Joseph Ratzinger, writing as an individual, without the magisterium of the Pontifical Office, provides the rational for what lies immediately ahead when he says:
"This demand for proof is a constantly recurring theme in the story of Jesus' life: again and again he is reproached for having failed to work that great miracle that will remove all ambiquity and every contradiction, so as to make it indisputably clear for everyone who and what he is or is not."
"And we make this same demand of God and Christ and his Church throughout the whole of history.
'If you exist, God,' we say, 'then you'll just have to show yourself.' You'll have to part the clouds that conceal you and give us the clarity that we deserve, If you, Christ, are really the Son of God, and not just another one of the enlightened individuals who keep appearing in the course of history, then you'll just have to prove it more clearly than you are doing now."
On page 34, Joseph makes a clear reference for the need for the Sign when he writes:
"Of course one can still ask why God did not make a world in which his presence is more evident - why Christ did not leave the world with another sign of his prenece so radiant that no one could resist it."
I was at a loss to understand why the Pope would write as an individual rather that as Pope. Having read the first few chapters I better understand why! He could not give his "guidance" the power of his office but yet he wants us to know he too believes God will not leave us orphan in this age of unbelief.
Jesus came as a man and understands perfectly how hard it is, in this "scientific age" to trust in what we cannot see or know definitively.
Joseph is also a man and understands how hard it is to trust. On page 38 he says:
"You know that the foundation of the world is love, so that even when no human being can or will help you, you may go on, trusting in the One who loves you."
It may be more difficult to trust in God today, when trust in some priests, nuns and bishops has been misplaced.
Could that be why Jesus would give us, through the intercession of the Blessed Virgin, a Warning, Miracle and Permanent Sign to reinforce our faith and trust in Him?