In the context of the letter to the Hebrews, this verse emphasizes the superiority of Christ's sacrifice over the repeated sacrifices of the Old Testament. The high priests of Israel had to enter the Most Holy Place every year on the Day of Atonement, carrying the blood of animals to atone for the sins of the people. This ritual had to be repeated annually because it was not sufficient to cleanse sin permanently.
In contrast, Jesus, as the ultimate High Priest, entered heaven itself, not with the blood of animals, but with His own blood. This act was not to be repeated, as it was perfect and complete. His sacrifice was once for all, providing a permanent solution to the problem of sin. This highlights the transition from the old covenant, which was based on repeated, temporary sacrifices, to the new covenant, which offers eternal redemption through Christ.
For believers, this verse reassures them of the sufficiency of Christ's work and the security of their salvation. It encourages faith in the completeness of Jesus' sacrifice and the grace that flows from it, offering a profound sense of peace and assurance in God's eternal plan.