How do we know that grace is necessary for understanding the Gospel?

The necessity of grace in understanding the Gospel is highlighted in John 9, where the blind man receives both physical sight and spiritual understanding through Jesus. This aligns with the broader theological truth that man, by nature, cannot perceive spiritual things unless God imparts that understanding. Salvation is a work of God from beginning to end; hence, grace is essential as it enables us to receive faith and understanding of the Gospel. The Lord tells us in Ephesians 2:8-9 that it is by grace we are saved through faith, not of ourselves, ensuring our understanding comes from Him alone.