Erlo Stegen emphasizes that God's ability to save is not limited, but our sins create a barrier between us and Him. The people in Isaiah's time were unaware that their disobedience was the reason for God's silence, believing instead that God had failed them. Stegen illustrates that sin is an affront to God's holiness and must be addressed for us to receive His help and guidance. He shares examples, including the Samaritan woman at the well, to demonstrate that acknowledging and confessing our sins is essential for restoring our relationship with God. Ultimately, the sermon calls for self-examination and repentance to remove the separation caused by sin.