What does the Bible say about Christ's suffering and atonement?

In 1 Peter 3:18, it is clearly stated that Christ also suffered once for sins, the just for the unjust, that He might bring us to God. This exemplifies the vicarious nature of Christ's atonement, meaning He suffered in our place as our perfect substitute. His suffering was not for His own sins — for He knew no sin — but for those of His elect. This unique and all-sufficient sacrifice fulfilled the requirement of God's justice, thereby redeeming His people from their sins and offering them reconciliation with the Father.