These are some of love's ways and attributes: to help, to redeem and to protect. Our patriarch Abraham is exalted in this blessing as the epitome of the loving kindness with which the whole creation is sustained.
We said in our commentary on Bereshit that the purpose of creation is to discover the Creator, and to know Him through His love as His light that created everything that exists. Then, why destruction should come from Him? We must understand that we have to go through transformation in the process of knowing the Creator, because revealing His concealed presence in the darkness also requires revealing Him in our consciousness.
Let's note that Japheth shall learn from Shem because all levels and dimensions of consciousness must follow our highest awareness of the Creator and His love.
The midrash says that his own father accused him in a court of law for denying and rejecting idolatry, and Abraham was sentenced to death in a crematory chamber. Then man's love meets God's love, and God saved Abraham from the flames in front of his executioners.