This idea is confirmed in Scripture; it is distinctly stated that one sole thing, fear of God, is the object of the whole Law with its affirmative and negative precepts, its promises and its historical examples, for it is said, "If thou wilt not observe to do all the words of this Law that are written in this book, that thou mayest fear this glorious and fearful name, the Lord thy God" (Deut. xxviii. 58) This is one of the two purposes of the Akedah (sacrifice or binding of Isaac).
Ch.24 - Guide for the Perplexed (c. 1190) - Part III