B.Spinoza asks whether we can we still gain moral instruction and inspiration from the Torah?
Well inspiration probably yes. Moral instruction probably not. I am not saying that the Torah has not been an important catalyst in the evolution of morality. I am sure it has, but the question is whether a person living in the 21 century should look to The Bible for moral guidance?
I do not really see much in The Bible that can teach a modern person how to live their lives. Morality in modern societies is far more developed than the Torah's morality. The Torah's morality in many places is rather crude, and typical of ancient societies. Chazal themselves had many a problem with the unsophisticated nature of biblical morality. Chazal quite rightly decided that 'an eye for an eye' is uncivilized and tried to convince us that the Torah had never meant to say that.
I think that we must divorce ourselves from our attitude towards Biblical morality. The Bible must not be our moral yardstick. Many things in The Bible are absolutely immoral (slavery, genocide of Ammoliek), and the morality that exists in The Bible is rather crude and unsophisticated.