Hebrews 9:22
Indeed, under the law almost everything is purified with blood, and without the shedding of blood there is no forgiveness of sins.

Reflection
This verse is often used as definitive proof that God 1) requires sacrifice through the shedding of blood to forgive, and 2) that Jesus is the only sacrifice acceptable to God, and 3) only those who receive forgiveness explicitly through Jesus can be forgiven–in other words, God can only forgive faithful Christians.
After the Roman Empire destroyed the Temple, animal sacrifice was no longer possible. Rabbis tell us that they transitioned from animal sacrifice as a primary spiritual practice to prayer, praise, and a life of love of neighbor as the sacrifice God desires (Hosea 6:6). In Hebrews, the author is working to help Jewish Christians make a very similar move.
It is true that some parts of the Jewish tradition focused on the importance and meaning of animal sacrifice. Hebrews references one of these traditions with this verse in part to honor the grief that Jewish people and Jewish Christians were experiencing at the loss of the Temple in 70 BCE. Then, the author lifts up the traditional, broader view that sacrifice is one of many spiritual practices that draw people closer to God and to each other (Eberhart and Schweitzer, p. 6).
Thus, it was necessary for the sketches of the heavenly things to be purified with these rites. Still, the heavenly things themselves need better sacrifices than these.
Hebrews 9.23
Hebrews honors the importance of sacrifice in the tradition. Hebrews quotes this verse but goes to say that sacrifice is not required to make God capable of forgiveness. To put it in Christian terms, sacrifice was a sacramental act. Sacraments offer humans a way to experience God’s love and forgiveness. Through them, God empowers us for lives of meaningful service. But God’s love is not dependent on sacraments. Rather, we experience God’s love in, through, and with them. A parent may express love through a hug, but the love is not limited to that hug.
The writer is proposing that people don’t need to offer animal sacrifice because God has drawn near to human beings in Jesus’ risking himself for the benefit of human beings.
Those that use this one verse as “proof” that Christianity is a divinely established exclusive in-group seem to not read the rest of the text. Nor do they seem to read the many other verses about sacrifice in the Hebrew Scriptures. This way-too-simple interpretation of a complicated book also seems to ignore the context and intent of the text: to help Jewish Christians find ways to faithfully practice their faith after the grievous loss of the temple. Where they once experienced at-one-ment with God in animal sacrifice, they can faithfully experience this in the spiritual practices of the Christian tradition.
Our Jewish neighbors did something similar, as Rabbi Wiener suggested in this section.