"Do you believe in the (sic) modern prophet?"
These were the words my cousin Brent asked me a few days ago through text. And because I wasn't that sleepy yet then, I decided to respond to his message not through text, but through writing.
Brent,
As suggested by the article "the", it is implied that you are talking about a particular person, or in this case, a prophet, as the noun is in its singular form: "the modern prophet". By then I would say, "No, I don't." Why?
In the Church's nearly two millenia of blessed existence, there had been countless heretics who led Christians astray from the pristine Catholic faith, as foretold by Matthew 24:5. Some of them claim to be the modern prophet, who, allegedly, have received divine revelations from our God. Some, like Joseph Smith Jr. (1805-1844), the founder of "The Church of Jesus Christ of Latter-Day Saints", which regards him as "the prophet of restoration (Joseph Smith.net, 2010)".
Here in the country, there are some people who are like him, too. One is Ptr. Apollo Carreon Quiboloy (1950-) from the Restorationist "Kingdom of Jesus Christ, The Name Above Every Name", who does not only claim to be God's prophet, but His own "appointed son (Kingdom of Jesus Christ.org)".
Another is Felix Ysagun Manalo (1886-1963) of the Iglesia ni Cristo (sic), whom the INC holds as "God's Messenger in These Last Days (Wikipedia, 2012)", claimed to be the "ravenous bird" described in Isaiah 46:11 (who is actually Cyrus the Great of Persia), and the "fourth angel" in the book of Revelation. His church also claims that they were "re-established" because the Catholic Church "strayed away from the pristine faith (This is the Iglesia ni Cristo, 1977)".
By "modern", I suppose you mean the time since the apostolic era. The three men I mentioned above lived more than a thousand years after the time of the Church Fathers, and all of them have established different "Christian" churches which, of course, hold on to some different doctrines.. Like all other 32,000 Christian confessions around the world, their churches hold their leaders/founders as their "modern prophet", like what Smith is to the Mormons and so on.
These so-called prophets used the 66-book "Bible" (the original Catholic Bible has 73) to support their varying claims about themselves and how God "foretold" their existence. They used the supposedly unifying agent as a divisive one, which, of course, Jesus did not want (John 17:21).
These prophets have followers, some who became pastors/ministers. They interpret the Bible on their own, not according to how the Church Jesus established upon St. Peter, 2,000 years ago, does so (Mt. 16:18).
I would have said "yes" if you replaced "the" with "a", or made it like "Do you believe in modern prophets?" All Christians should be modern prophets, that is, by proclaiming God's greatness, love, and mercy to all the ends of the earth. Not to start a schism, but to bring them to God's family here on earth, the One (1 Cor 1:10), Holy (Eph 5:27), Catholic (Mt 28:19), and Apostolic (Mt 16:18, 28:20) Church. When we were baptized, we shared in the threefold mission of Our Lord Jesus Christ as king, priest, and prophet. We ought to do our part until our last breath.
But until then, it is a "no". Why would I believe in people (and their teachings) ought to divide the Church?
I do hope this long post has answered your question. I would be happy to answer more some time.
May God bless you and your family, now and forever.