If we believe the Bible is God's revelation to us, then we believe that the first man was Adam. Scriptures tell us that Eve "was the mother of all living" (Genesis 3:20). In the New Testament, Christ and the other writers reference accounts in Genesis, including Adam, Eve and the worldwide Flood, as the beginning of human history. In 1 Corinthians 15:20-22, 45, 47, for example, God tells us that the first man was Adam. All humans are created in the image of God, come under judgment of God and are appointed to die once.
But what about human-like fossils that scientists say predate Adam? First, we need to understand that science often presents theories in ways that suggest they are facts when they are really still theories. There are also serious problems with radiometric dating—one of the so-called proofs of the age of these fossils. Some fossil bones that evolutionists claim to be those of prehistoric humans are probably from monkeys or other animals. Misshapen bones can also be from humans who suffered from diseases such as rickets, which distort the bones.
Whatever creatures may have lived prior to Adam and Eve, and however closely they may resemble the human form (such as gorillas or monkeys do), it is a misnomer to call them "men." The Bible says man was created by God, in the image of God, at the time of Adam and Eve. Man was made to be offered eternal life in the very family of God, made to come under judgment, and only man was promised a resurrection from the dead. Anything that came before Adam should not be called "man." Other life forms, including dinosaurs, likely existed prior to Adam and Eve—but Adam and Eve were the first humans as we know them today.