This is a very broad question and impossible to answer in a few sentences. Do you mean it in a personal or historical context?
If I talk just for myself, I have to say useful. Trying to strive for Christian ideals made me definitelly a better and more stable person in a culture that is increasingly relativistic; and when people have difficulty making their everyday decisions I appreciate the simple, basic guidelines for life as taught by Jesus.
If you look at the histirical context you can certainly take it either way. We live in a culture where Christian ideas are caricatured and ridiculed in media and sophisticated society so it is easy and popular to portray Christians as stupid, uneducated, hateful and so on, and to emphasize only the bad examples (crusades, inquisition. witch hunts, treatment of Galileo, Hitler being Christian). But we have to remember that the most progress in science, medicine, prison reforms, care for the marginalized, racial equality, working conditions,... was achieved in so-called Christian countries by people who were believing Christians. Just a few examples:
Michael Faraday(electricity, magnetism), W.T. Kelvin (physics), A. Fleming (penicillin), L. Pasteur, Father N. Copernicus, Monsignor Lemaitre (Big Bang theory), Catholic monk G. Mendel (genetics), W. Wilberforce (anti-slavery movement), Lord Shaftesbury (social reforms), Elizabeth Fry (prison rreforms), F. Nichtingale (care for the sick and dying).....................
They achieved great things not in spite of being Christians but because they were Christians and their faith in God and Jesus Christ moved them to study nature (God's creation) and help other human beings (created in God's image).