It is in the face of the humiliation of Christ, the humiliation of the manger, that Paul talks about our need for conformity to the example of our Lord. The great precept that is pressed upon us is to love one another.
Christian love is a mutual love.
The same love that we are required to express to others, others are bound to express to us. The humiliation of Christ was simply the humanity of it. It was His humanness that was humiliating. He emptied Himself and made Himself nothing. He who knew all subjected Himself to limitations of mind in body.