From Edwin Hatch’s “The influence of Greek ideas and usages upon the Christian church“:

It is impossible for any one, whether he be a student of history or no, to fail to notice a difference of both form and content between the Sermon on the Mount and the Nicene Creed. The Sermon on the Mount is the promulgation of a new law of conduct ; it assumes beliefs rather than formulates them ; the theological conceptions which underlie it belong to the ethical rather than the speculative side of theology; metaphysics are wholly absent. The Nicene Creed is a statement partly of historical facts and partly of dogmatic inferences ; the meta-physical terms which it contains would probably have been unintelligible to the first disciples ; ethics have no place in it. The one belongs to a world of Syrian peasants, the other to a world of Greek philosophers.