How do we know God's grace is not in vain?

In 1 Corinthians 15:10, Paul states that while he worked harder than others, it was ultimately God's grace that enabled him to labor effectively. This indicates that true grace results in a life that reflects God's character and produces significant spiritual fruit. Grace is not merely about forgiveness; it is transformative, empowering believers to deny self and live righteously. A life marked by humility and service is a testament to the effective work of God's grace within us. Therefore, when we see the fruit of the Spirit manifest in our lives, we can be assured that God’s grace is at work and not in vain.