Why would God give prophets in the Old Testament and not today?
"God, who at sundry times and in divers manners spake in time past unto the fathers by the prophets, Hath in these last days spoken unto us by his Son, whom he hath appointed heir of all things, by whom also he made the worlds" (Hebrews 1:1-2).
The Bible teaches that Jesus is to be considered a prophet (e.g., Luke 24:19). Certainly He is more than a prophet, but He is at least a prophet. He "is the same yesterday, today, and forever" (Heb. 13:8), and since He lives forevermore (Heb. 7:24), He is still our Prophet today.
Some LDS wonder if traditional Christianity is true, then why would God love the people in the Old Testament more by giving them prophets and not us today? Actually, who God loves more is not the issue. The issue is instead the unfolding of God's program in His timing. LDS must recognize this, since even they think there are benefits today that the Old Testaments saints did not experience. For example, LDS think there are benefits of black men having the priesthood today. Of course most LDS would never claim that God loved the people in the Old Testament more since blacks were never allowed the priesthood until 1978. Or what about, "Did God love the people in the Old Testament more since they were able to sacrifice animals when we get this proscribed to us?"
Now even though Jesus is our ultimate Prophet who reveals the gospel to the world through His Church, there are still those in the New Testament that are called prophets. Anna was a New Testament prophetess (Luke 2:36), Phillip had four daughters who were prophetesses (Acts 21:9), and then Agabus was also considered a prophet (Acts 21:10). There are gifts of prophecy in the New Testament Church, and those who have these gifts are called "prophets."
LDS will make the arbitrary claim that these were only prophets in the general sense in which they gave forth the word of God, but there still needed to be just one individual at a time who served as the head prophet/president. What LDS fail to see is that in this sense, we have our head prophet today, viz., our Lord Jesus Christ. The Bible never demands that there always be only one prophet for God's people other than Jesus. God may have done this at some point in the past (e.g., Moses leading the children of Israel), but there were also times where God also had more than one individual prophet leading Israel (e.g., Haggai and Zechariah were prophets together in Ezra 5:1).
Because we have our Prophet who has given us His word and has promised to preserve it (Matthew 24:35), and because He continues to speak through other prophets today, we do not have to worry that He has left us orphaned. He promised that He would continuously protect His Church from the attacks of hell (Matt. 16:18). The faith has been "once delivered unto the saints" (Jude 3). The Church of God in all its various manifestations stands against those false prophets like those of the LDS Church who promote a false god, false Jesus, and false scriptures. Galatians 1:6-9 says, "I marvel that ye are so soon removed from him that called you into the grace of Christ unto another gospel: Which is not another; but there be some that trouble you, and would pervert the gospel of Christ. But though we, or an angel from heaven, preach any other gospel unto you than that which we have preached unto you, let him be accursed. As we said before, so say I now again, if any man preach any other gospel unto you than that ye have received, let him be accursed."
R. M. Sivulka