Adam spoke directly to God in the Garden of Eden. When he left the garden, he was still able to communicate with God through prophecy. The Bible is the record of the teachings of the prophets from that time until the death of the last apostle.
There were times when the people of the Bible were without prophets. When they were wicked and refused to listen to or obey the prophets, God took the prophets from them. Later, he would send a new prophet and give them the opportunity to again have direct guidance from God. After the last apostle died, however, a great apostasy began. Due to the refusal of most of the world to honor the divinity of God’s greatest gift, the world was left without the benefit of a prophet. They managed to keep Christianity alive, but divisions quickly arose, because there was no one to explain the meaning of scripture or to guide when new situations not covered by the Bible arose. In short time, there were many different churches, all teaching different things, but all professing to teach what the Savior taught.
Of course, truth is absolute, and when there are contradictions, we know the truth has been lost or corrupted. Because these are the final days before the Second Coming, God knows we need to a prophet to safely prepare for this eternally significant event. He restored the prophets along with the gospel through Joseph Smith.
A prophet today fulfills the same role as the prophets of ancient times. They speak to us for God, communicating His truths and His instructions.
One thing many today forget, as they study the church, is that a prophet is not divine. He is a man, and therefore an imperfect person, since only the Savior lived on the earth without sin or mistake. While a prophet is certainly called upon to live to a high standard, he is not perfect. Just as Jonah tried to hide from God, and Moses was afraid to speak due to speech challenges, today’s prophets face their own challenges and must learn, grow, and progress toward perfection as does anyone else.
They are also not prophesying or representing the church every time they speak. Every word that comes from a prophet’s mouth is not doctrine. For instance, if a prophet, opening a meeting on a church-owned campus, expresses confidence that the football team will win their game this week, he is not prophesying their win. He is simply expressing a human hope, as would any other fan of the team. Prophets, especially in the earlier days of the church, often speculated and wondered about things God had not revealed. Sometimes these were recorded by congregation members or other listeners and published. As a result, Mormons are often thought to believe things that were really just the wonderings of intelligent men.
Today, with the advent of extraordinary communications abilities, prophets are more cautious about making clear the difference between fact and wonderings, but they do say many things that are never canonized. It’s important, when studying Mormonism, to find out what is doctrine and what is wondering, and also what is core doctrine. In general, core doctrines are those which directly impact our eternal salvation. Other things, such as the age of the earth or how many people were on the American continent when the people of the Book of Mormon people arrived, are simply matters of curiosity among church members. Knowing the answers would be interesting, but would have no direct impact on our salvation, and so, are not the subject of prophecy.
Because Mormons believe in continuing revelation, they often receive new council from their leaders. Just as prophets in the Bible gave new teachings and directions-the Beatitudes replacing much of Judaic law, for instance-Mormons also receive new council as situations and needs change. When evaluating what you’ve heard Mormons believe, be certain to check the date of the revelation. The words of the most current prophet are those that members are held accountable for.