Christ’s death was not an atonement and the New Testament never speaks of it this way. The blood of bulls and goats covered sin, but those sacrifices had to continually be offered because atonement wasn’t enough.
Christ died once and He did not cover sins, He removed them. The classic text to grasp this distinction is Hebrews 10. Here are the highlights:
10:1–those sacrifices can never make the comers thereunto perfect
10:4–it is not possible that the blood of bulls and of goats should take away sins
10:6–God had no pleasure in burnt offerings and sacrifice
10:10–we are sanctified by the body of Christ once for all
10:12–Christ offered His body one time as a sacrifice for sin
10:14–by one sacrifice He perfected forever those that are sanctified
10:17–God will not remember sins and iniquities any more
10:18–where remission of sins is there is no more sacrifice
Christ’s death is not an atonement, it is a removal of sin, which is completely different and, in fact, the whole point of Hebrews 10! We are placed in Christ, sanctified to Him, and are thus free from sin as He is.
The fact that we go on calling His death “Substitutionary Atonement” is merely one more example of theology gone bad. Words mean things. Why do we use a word to describe Christ’s death that the Bible does not use in that context and goes to great lengths to prove is way better than that word?!
We need to think rightly. To understand God, we must understand Him according to what He has revealed of Himself. Don’t mess with what has been revealed.