Under the Law given to Israel, once a year the high priest would make s sacrifice to atone for ALL the sins of the people of Israel, intentional and unintentional. That day was called the day of Atonement and God would forgive all sins committed during the previous year. (Leviticus 16)
We are told that these offerings were temporary in that they did not “take away" future sins.
“Every priest stands daily ministering and offering time after time the same sacrifices, which can never take away sins.” (Hebrews 10:11)
The Law requires sacrifices to be made year after year for the sins of the people. BUT not anymore! God the Father brought the final sacrificial offering to atone for the sins of the whole world, past and future. That offering was His Son, the sacrificial perfect Lamb of God, Jesus. That sacrificial offering has taken away the sins of all humanity!
“He Himself is the atoning sacrifice for our sins; and not for ours only, but also for those of the whole world.” (1 John 2:2)
God the Father has saved humanity by His GRACE! We are to have faith in our salvation. His compassion and mercy never fails, they are new every morning.
“So that in the ages to come He might show the surpassing riches of His grace in kindness toward us in Christ Jesus. For by grace you have been saved through faith; and that not of yourselves, it is the gift of God; not as a result of works, so that no one may boast.” (Ephesians 2:7-9)