"For the life of the flesh is in the blood, and I have given it to you upon the altar to make atonement for your souls; for it is the blood that makes atonement for the soul."
God will only accept shed blood as atonement for sin. Nothing else will do--not works, not religion, not self-deprecation. The blood of animals sacrificed under the Old Covenant only pointed to the true and only satisfactory blood atonement, which would be offered on the cross by the sinless God-Man, Jesus Christ, who is the "Lamb of God," (Jn. 1:29).
The Lord is *only* pleased with us--and views us as forgiven--as our souls are "covered" by Christ's blood. The only way to appropriate this blessed atonement is by grace through faith (in Christ).
[Puritan quote of the day: "Never since the beginning of the world have their been such glorious times as we enjoy." --Richard Sibbes, in "Glorious Freedom"]