In this book of Romans we have seen Paul use such men as Abraham(faith) and Moses(Law) the two great patriarchs of the Jewish faith. We who follow Christ are even called sons of Abraham. So now Paul reaches way back to the beginning and uses Adam to explain our dilemma and the solution. It is Adam and Christ contrasted.
Adam and the Presence of Sin in the World
Romans 5:12 (NKJV) " Therefore, just as through one man sin entered the world..."
Paul says that sin entered into the world through one man and in verse 14 he tells us that one man is Adam.The story of Adam and Eve is no mere myth, folklore or legend but an actual event in human history.
Please note what it say, sin entered the world through Adam. Sin did not originate with Adam it originated through Lucifer.