Why are there no more prophets? The torah promises Moses that he would have a successor, which the meforshim understood as being in all generations. The text implies this too. The skeptic is tempted to think that there never were any prophets, hence there are not any today. The Vilna Gaon claims that there is no need fo prophecy anymore - but that is a very poor argument, we need them, perhaps more than ever.
There will be a return of prophecy with the full redemption (Hilchot Melachim ch.12). During our exile there can be no prophecy; a requirement for prophecy is joy. When we are under the yoke of the nations among whom we are dispersed- nations who, according to Maimonides are afflicted by every weakness of mind and morals- what full joy can there be (Guide to the Perplexed III 36)? If the absence of prophecy really troubles you and you want to actively take a role in restoring prophecy, join us here in Israel as we rebuild the Jewish People in its own Land!