How can we be sure Christ's sacrifice was enough for salvation?

The assurance of salvation is grounded in the nature of Christ's sacrifice. As Hebrews 9:12 explains, Christ entered the holy place once by His own blood, which signifies that no further offerings are necessary. This is a stark contrast to the repeated sacrifices under the old covenant, which could not perfect the worshippers. Christ's sacrifice accomplished the work of redemption completely and definitively, assuring us that our faith in Him is sufficient for salvation, as it rests on His accomplished work rather than our own.