25 God presented him as a sacrifice of atonement, through faith in his blood. He did this to demonstrate his justice, because in his forbearance he had left the sins committed beforehand unpunished (Romans 3:25)

17 For this reason he had to be made like his brothers in every way, in order that he might become a merciful and faithful high priest in service to God, and that he might make atonement for the sins of the people. (Hebrews 2:17)

My dear children, I write this to you so that you will not sin. But if anybody does sin, we have one who speaks to the Father in our defense—Jesus Christ, the Righteous One. 2 He is the atoning sacrifice for our sins, and not only for ours but also for the sins of the whole world. (1 John 2:1-2)

10 This is love: not that we loved God, but that he loved us and sent his Son as an atoning sacrifice for our sins. (1 John 2:4:10)