6 Bible Verses about Atonement, Made Once

who has no day by day need, like those high priests, to offer sacrifices, first of all for his own [personal] sins and then for those of the people, because He [met all the requirements and] did this once for all when He offered up Himself [as a willing sacrifice].

For Christ did not enter into a holy place made with hands, a mere copy of the true one, but [He entered] into heaven itself, now to appear in the very presence of God on our behalf; nor did He [enter into the heavenly sanctuary to] offer Himself again and again, as the high priest enters the Holy Place every year with blood that is not his own. Otherwise, He would have needed to suffer over and over since the foundation of the world; but now once for all at the consummation of the ages He has appeared and been publicly manifested to put away sin by the sacrifice of Himself. read more.
And just as it is appointed and destined for all men to die once and after this [comes certain] judgment, so Christ, having been offered once and once for all to bear [as a burden] the sins of many, will appear a second time [when he returns to earth], not to deal with sin, but to bring salvation to those who are eagerly and confidently waiting for Him.

And in accordance with this will [of God] we [who believe in the message of salvation] have been sanctified [that is, set apart as holy for God and His purposes] through the offering of the body of Jesus Christ (the Messiah, the Anointed) once for all.

whereas Christ, having offered the one sacrifice [the all-sufficient sacrifice of Himself] for sins for all time, sat down [signifying the completion of atonement for sin] at the right hand of God [the position of honor],

For by the one offering He has perfected forever and completely cleansed those who are being sanctified [bringing each believer to spiritual completion and maturity].

For indeed Christ died for sins once for all, the Just and Righteous for the unjust and unrighteous [the Innocent for the guilty] so that He might bring us to God, having been put to death in the flesh, but made alive in the Spirit;