How do we know that Jesus' death secured salvation?

The certainty of salvation through Jesus' death is rooted in both God's sovereign purpose and His willingness to suffer. Isaiah 53:10 states that it pleased the Lord to bruise Him, meaning that His death was part of God's eternal plan for redemption. Moreover, the New Testament reaffirms this, with Romans 1:16 declaring the Gospel as the power of God for salvation. This dynamic power is linked to Christ's willing obedience, as He lay down His life as a voluntary act of sacrifice in accordance with God's will. The fulfillment of prophetic Scripture further assures us that His death was effective in securing salvation for those whom the Father has given Him.