How do we know that Jesus’ sacrificial death is effective?

The effectiveness of Christ's sacrificial death is rooted in Scripture, particularly in John 5:21-24, where Jesus states that the Father raises the dead and gives life to whom He wills. The belief that Jesus' sacrifice is sufficient for salvation is a cornerstone of Reformed theology, emphasizing that it is not based on human merit but divine grace. His resurrection serves as a divine endorsement of His sacrificial death, validating the assurance that 'he that heareth my word, and believeth on him that sent me, hath everlasting life.' This illustrates that salvation is a gift from God, received through faith alone, ensuring that His death at the cross achieves its intended purpose of redeeming those chosen by Him.