"We are told that Christ was killed for us, that His death has washed out our sins, and that by dying He disabled death itself."

Bronzino's Christ on the Cross, 1545
Public DomainBronzino's Christ on the Cross, 1545
Verses below are quoted from the English Standard Version.

“Christ was killed for us”

Romans 5:8-11: But God shows his love for us in that while we were still sinners, Christ died for us. Since, therefore, we have now been justified by his blood, much more shall we be saved by him from the wrath of God. For if while we were enemies we were reconciled to God by the death of his Son, much more, now that we are reconciled, shall we be saved by his life. More than that, we also rejoice in God through our Lord Jesus Christ, through whom we have now received reconciliation.

1 John 4:9-10: In this the love of God was made manifest among us, that God sent his only Son into the world, so that we might live through him. In this is love, not that we have loved God but that he loved us and sent his Son to be the propitiation for our sins.

Cf. Romans 4:23-25

“His death has washed out our sins”

Romans 3:23-26: For all have sinned and fall short of the glory of God, and are justified by his grace as a gift, through the redemption that is in Christ Jesus, whom God put forward as a propitiation by his blood, to be received by faith. This was to show God’s righteousness, because in his divine forbearance he had passed over former sins. It was to show his righteousness at the present time, so that he might be just and the justifier of the one who has faith in Jesus.

Cf. Leviticus 17:11; Colossians 1:13-14; Hebrews 9:11-12; 1 John 1:7; Revelation 1:4-6.

“He disabled death itself.”

John 8:51: “Truly, truly, I say to you, if anyone keeps my word, he will never see death."

Hebrews 2:14: Since therefore the children share in flesh and blood, he himself likewise partook of the same things, that through death he might destroy the one who has the power of death, that is, the devil.

Cf. 1 Corinthians 15; Philippians 1:19-26