How do we know that salvation is completed through Christ?

Salvation is completed through Christ as demonstrated in Scripture. Hebrews 10:12 states, 'But this man, after he had offered one sacrifice for sins forever, sat down on the right hand of God.' His sitting down indicates the finished nature of His sacrifice; there is no further sacrifice needed. Additionally, through His obedience and fulfillment of the law, Jesus magnified the law and made it honorable (Isaiah 42). As the Lamb of God, He bore the sins of all His people, which encompasses transgressions, sins, and iniquities, thus achieving reconciliation and bringing in everlasting righteousness (Daniel 9:24). Therefore, believers can rest assured that their redemption is fully secured in Christ's completed work.