To understand the gospel we must understand what we are saved from. This passage teaches that apart from salvation all of mankind is unrighteous before God. It shows us a number of the characteristics of our sinfulness and confronts us with the truth that we are all accountable to God. The passage makes it clear that there is no hope of salvation from man’s side. We need to be rescued. The verses and chapters that follow describe how God does this in Christ.
Read Romans 3:9-20