How do we know that Christ's death was effective for our salvation?

The effectiveness of Christ's death for our salvation is rooted in His sinlessness and perfect righteousness. As stated in the sermon, if a sinful person were to take another's punishment, justice would not be satisfied. However, because Christ was innocent and fully righteous, His death on the cross bears the weight of our sins effectively. The integrity of His life adds saving efficacy to His sacrifice; thus, we can declare with confidence that His atoning work reconciles us to God and provides the only basis for our justification.