"Yes, Father, for thus it was well-pleasing in Thy sight." Why does it please God to identify with the lowly and despised? Here is my best intuitive guess. Put yourself in God's shoes. He is the almighty one. No one resists his will. He is the beginning and the end of all things, he has the final say. But he also seeks to glorify himself before angels and men. Now, at the end of redemptive history we know that the victory will belong to him, but how will that victory be achieved? God is not willing to achieve victory using his raw power, just smashing the Devil and his demons and anyone else who defies him. It's too obvious, and it doesn't do justice to the fullness of who he is. So he allows himself to be beset, to be mocked, to be delayed by the workings of evil for a time. Through it we see a different side of God that we never could have imagined before. A God who suffers. A God who is patient in the face of evil. A God who makes his home in the hearts of the weak and sinful and ignorant. By doing so, somehow his power and holiness and wisdom seem that much richer. All the hidden depths of God character are revealed and glorified in a way that could not have been otherwise. The angels who already worship and praise him do so with greater awe.
"No one knows the Son except the Father, nor does anyone know the Father except the Son and anyone to whom the Son wills to reveal him." This is the Father whom the Son reveals to us: the God who seeks out the lost, enters into our sorrows, cleanses our filth and carries away our diseases. If you recognize this God you have been given true sight, you've been healed of your blindness. But if you only know a God who is hard and demanding, nothing but a relentless display of fearsome power, you haven't truly seen him. You're still stumbling around in the dark.