This book offers some of the best insights into how to best understand a vast variety of Christian issues in a contemporary way. It is generally attributed to Paul, but we don't really know that since unlike Paul's epistles, it is not a clear letter from him to a group of people. Some claim it was either a sermon or collection of messages Paul spoke, but even that is not fact. The early church seems to have totally accepted this writing as a clear message from God, but seems to have shown little concession as to whom the author was. Sadly, the King James version added words that implied this Scripture was for sure from Paul. So who cares? Well, first, adding to the Bible or implying fact that is not certain is a dangerous pattern with Scripture as in the end it is God's words. The real concern is that this is a letter that was written to the church in Rome from someone who was, at the least, a close associate of Paul.
Rome was a very remote small church at the time this letter was written. Key beliefs were not accurately making the voyage to Rome and the church seems to have been heavily influenced by other groups including the Jewish church, Roman beliefs, Hellenistic beliefs (Greek), and emerging cults from various groups including Christian offshoots such as the Gnostic movement. Hebrews clearly is written with the intention to say, "Wait a minute! These is the true teachings of God." That makes this a very important scripture for Christians to study as this document literally exists to teach us key beliefs of Christianity. Perhaps it would best be labeled a "systematic theology book." Really, the church of Rome was much like the church today--it was under attack from all sides.
So what does that have to do with today's Scripture? Well, the first four verses of the book simply seek to clarify that Jesus is God, above the angels, and is eternal. Most importantly it stresses we can trust Jesus.