How do we know that Christ's sacrifices are sufficient for salvation?

Hebrews 9:12 emphasizes that Christ, by His own blood, entered into the holy place once and obtained eternal redemption for us, which affirms that His sacrifice was sufficient and complete. Unlike the continuous sacrifices of the Old Testament, which had to be repeated yearly, Christ's single sacrifice fulfills the requirements of the law for all those He represents. This eternal aspect means that His work does not need to be redone; it is complete in itself and effective for the redemption of His people at all times.