I see 4 classes of people in Romans 1-5. (These actually correlate to 4 horses in the book of Revelation)
The first group are people who rejected the instinctive law of God within their conscience resulting in a continuous degradation deeper and deeper into open sin.
The second group of people are religious people who trust in their knowledge about religion and compare themselves with the open sinners through judgment in order to make themselves appear righteous.
Third group are those who do not know much about God, are not part of the religious establishment but who listen and follow their conscience quietly led by the Spirit of God unknown to them.
The fourth group are those gathered from all the previous groups who have accepted the reconciliation to God provided by Jesus, trusting in His righteousness fully and not at all in their own, and who seek for God's glory. Their focus is on God and what He does and believe in His abilities to do what He says He can do in our lives. Like Abraham they hope even when there is no apparent reason to hope, they praise God for who He is and not just for His obvious blessings – they live a life of faith that is a response to the faith God has in them. Instead of condemning others in judgment over them they celebrate what God can do for them. Instead of pious boasting about their own “righteous” lives they glorify God for His righteousness, goodness, faithfulness, grace and mercy. As they believe in God's ability to do the seemingly impossible they themselves come to be considered righteous in the eyes of heaven. As a result this righteousness in their hearts accepted by faith starts appearing in their life in the externals. They find themselves at peace with God, something that the first three groups do not experience. (see 1:18-22, 2:3-6, 2:15, 5:1)