I would encourage to read this passage from St Gregory Nazianzen slowly and carefully a couple of times through.
newadvent.org/fathers/310245.htm
Ransom, punishment and guilt should be properly understood, yes. Thank you for the quotation, very interesting, that can be conciliated with the Catechism.
âHe died for our sins in accordance with the Scripturesâ
601 The Scriptures had foretold this divine plan of salvation through the putting to death of âthe righteous one, my Servantâ as a mystery of universal redemption, that is, as the ransom that would free men from the slavery of sin.397 Citing a confession of faith that he himself had âreceivedâ, St. Paul professes that "Christ died for our sins in accordance with the scriptures."398 In particular Jesusâ redemptive death fulfills Isaiahâs prophecy of the suffering Servant.399 Indeed Jesus himself explained the meaning of his life and death in the light of Godâs suffering Servant.400 After his Resurrection he gave this interpretation of the Scriptures to the disciples at Emmaus, and then to the apostles.401
âFor our sake God made him to be sinâ
602 Consequently, St. Peter can formulate the apostolic faith in the divine plan of salvation in this way: "You were ransomed from the futile ways inherited from your fathers. . . with the precious blood of Christ, like that of a lamb without blemish or spot. He was destined before the foundation of the world but was made manifest at the end of the times for your sake."402 Manâs sins, following on original sin, are punishable by death.403 By sending his own Son in the form of a slave, in the form of a fallen humanity, on account of sin, God "made him to be sin who knew no sin, so that in him we might become the righteousness of God."404
IN BRIEF
619 âChrist died for our sins in accordance with the scripturesâ (I Cor 15:3).
620 Our salvation flows from Godâs initiative of love for us, because âhe loved us and sent his Son to be the expiation for our sinsâ (I Jn 4:10). âGod was in Christ reconciling the world to himselfâ (2 Cor 5:19).
621 Jesus freely offered himself for our salvation. Beforehand, during the Last Supper, he both symbolized this offering and made it really present: âThis is my body which is given for youâ (Lk 22:19).
622 The redemption won by Christ consists in this, that he came âto give his life as a ransom for manyâ (Mt 20:28), that is, he âloved [his own] to the endâ (Jn 13:1), so that they might be âransomed from the futile ways inherited from [their] fathersâ (I Pt 1:18).
623 By his loving obedience to the Father, âunto death, even death on a crossâ (Phil 2:8), Jesus fulfills the atoning mission (cf. Is 53:10) of the suffering Servant, who will âmake many righteous; and he shall bear their iniquitiesâ (Is 53:11; cf. Rom 5:19).