How do we know that we need grace as sinners?

The acknowledgment of our need for grace stems from understanding our fallen condition as outlined in Romans 7, where Paul describes his internal struggle as a sinner. He recognizes that in his flesh dwells no good thing and that the law reveals his inability to achieve righteousness. Furthermore, the sinful nature manifests itself through our daily thoughts and actions, reminding us of our need for a Savior. The grace of God, offered freely through Christ, is what provides justification and reconciliation for the believer, highlighting the necessity of grace in our lives.