How do we know that salvation is complete in Christ?

The assurance that salvation is complete in Christ comes from the authoritative testimony of Scripture. In Romans 3:26 and Hebrews 10:12, we see that Christ's sacrifice is once for all, affirming the completeness of His atonement. The declaration of 'It is finished' signifies that all necessary provisions for sin have been met, leaving no room for additional sacrifices or works. This assurance is pivotal for believers, allowing them to rest in the sufficiency of Christ's work for their salvation.