How do we know that Jesus accomplished redemption for His people?

The assurance of Christ's redemptive work is found in His promise to lay down His life specifically for His sheep, as stated in John 10:15. This act was not a mere attempt but an absolute accomplishment that secured eternal life for all whom the Father had given Him. The justice of God demands that those for whom Christ died must be granted salvation and new life. This is seen in Romans 5:15-19, where the act of Christ's obedience brings justification and life to many. The sovereignty of God in salvation ensures that none of the elect will perish, for Christ intercedes on their behalf.