There is a stark contrast between being a debtor and an heir. To be a debtor you owe something. In the case of our soul, death is the payment for those who live in or by the flesh. Romans 8:12-17 compares that debt owed if our lives are lived in the flesh to that fact that we are given something when we live in the Spirit. We are made heirs of God if we are led by the Spirit of God. We are sons of God. Verse 13 "For if you live according to the flesh you will die, but if by the Spirit you put to death the deeds of the body, you will live." We become adopted sons "by whom we cry, "Abba! Father!" We are "heirs of God and fellow heirs with Christ, provided we suffer with Him in order that we may also be glorified with Him."
Are we living in the flesh or in the Spirit of God? Are our sins in control or are we striving to please God with our lives? Are we fleeing sin on a daily, hourly, minute by minute basis? I'm not saying we will ever reach perfection. But I think too often we fall back on that excuse are think, "welp, I'm a sinner." Instead we need to be angry with our sin. That is probably the only way we can have justified anger. Be mad at your sin. It is a battle we must wage even every second of our lives. We need to listen to the Spirit's prompting. We need to continually focus on God and His will for our lives.
Praise God for His Adoption, that we can be heirs with Christ.