Why did Baha’u’llah bear such incredible ordeals, calamities and sorrows?

... the Blessed Perfection bore all these ordeals and calamities in order that our hearts might become enkindled and radiant, our spirits be glorified, our faults become virtues, our ignorance be transformed into knowledge; in order that we might attain the real fruits of humanity and acquire heavenly graces; in order that, although pilgrims upon earth, we should travel the road of the heavenly Kingdom, and, although needy and poor, we might receive the treasures of eternal life. For this has He borne these difficulties and sorrows. (Abdu'l-Baha, The Promulgation of Universal Peace, p. 28)