How do we know salvation is the work of Christ?

Throughout Scripture, particularly in the creation account in Genesis 1:6-8, we see symbolic representations of Christ's work in bringing salvation. The firmament that separates the waters above from the waters below illustrates how Christ stands as the dividing line between the righteous and the unrighteous. Only through Christ's sacrificial death and subsequent resurrection do we have the assurance of salvation. His fulfilling of the law and payment for sin offers unconditional acceptance into God's presence, validating that salvation is completely a work of Christ, not dependent on our own efforts.