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

The effectiveness of Christ's death for salvation can be observed through the understanding of God's justice and mercy. In Isaiah 53:10, we learn that it pleased the Lord to bruise Him, making Him an offering for sin, thus affirming that His sacrificial death met the divine demands of justice. The exaltation of Christ serves as the evidence of this effectiveness; by raising Him from the dead and seating Him at His right hand, the Father affirmed that the payment for sin was sufficient. The assurance of our salvation relies on this truth, as seen in Hebrews 1:3, where it states that He sat down at the right hand of God after purging our sins, indicating His work was complete and accepted.