Hebrews 7:27-28
He does not need to offer up [animal] sacrifices every day like those head priests did [Note: The head priest here is represented as being in charge of the daily sacrifices offered by the other priests], first for His own sins and then for the people's sins. For He did this once for all time when He offered up Himself [on the cross].
Romans 8:3
For what the law was not able to do [for mankind], since it was [too] weak [to deliver them from condemnation] because fleshly people [were unable to obey it perfectly], God condemned sin in the flesh [i.e., sin was declared evil and its power over man broken]. God did this by sending His own Son in a body like sinful man's, and to destroy sin,
2 Corinthians 5:21
God considered Christ to be sinful on our behalf, even though He never sinned, so that we could be considered right with God through Him.
Hebrews 5:3
And because of this he is obligated to offer [sacrifices] for his own sins also, as well as the people's sins.