Three encyclicals that prove his affinity for the Redeemer, and his conviction that (in addition to Divine Mercy) redemption was the message for the modern world are: Remptor Hominis, Redemptoris Missio, and Redemptoris Mater. All three refer to the mystery of Redemption and its implications for man (both individually and collectively). I want to largely draw from the first two of these encyclicals in order to illustrate the profound relationship JPII had with the Redeemer, who paid for the Church with the gift of his own blood.
The 'mystery' of the Redemption is precisely that, a mystery, but it is still worth mining for truth, goodness, and beauty under the guidance of the Slavic Pope who explored the mystery so thoroughly. That is to say that the mystery is very much accessible to the layman with the help of the wisdom of the holy father. Therefore, it is safe to proceed with the basic understanding of Redemption as the price paid for man to be reconciled to God.
As the Redeemer, Jesus paid the price of his blood on the cross without reservation, and once dead, was raised on the third day in victory over sin and death. I want to emphasize, as does the Pope, that the Resurrection justified the price of Jesus' blood on the cross with inestimable value, efficaciousness, and life-giving centrality to the Church. JPII's very first encyclical began with these words: "THE REDEEMER OF MAN, Jesus Christ, is the center of the universe and of history" (Redemptor Hominis, ch. 1). Furthermore, in the sacraments, especially of baptism and the eucharist, we encounter the power of the Redemption firsthand:
By celebrating and also partaking of the Eucharist we unite ourselves with Christ on earth
and in heaven who intercedes for us with the Father, but we always do so
through the redeeming act of his Sacrifice, through which he has
redeemed us, so that we have been "bought with a price". The "price" of
our redemption is likewise a further proof of the value that God himself
sets on man and of our dignity in Christ. (ibid, ch. 20)
This statement in itself, comprises the whole of the message of Redemption which JPII wished to impart to the world. It was as though the Redeemer urged him to "tell my people that I value them to such a degree that I entirely spent my priceless blood for each of them". The message is very much in line with scriptural and traditional understanding of redemption as 'purchasing', and demands to be delivered with a particular urgency in a world where human dignity has all but been reduced to mere numeric value. Further evidence from Scripture for this same understanding of redemption appears in the books of Ruth and Exodus in particular, foreshadowing Christ as Bridegroom in the former and Christ as Redeemer from slavery in the latter.
Karol Wojtyla saw the worst of ideological indignity in nazism and communism. Yet, he found himself being led by the Redeemer, in the midst of both catastrophes, to communicate the message of Redemption to the world threatened by the allurement of such inhumanity. He challenges man, so strongly influenced by the likes of Freud, Nietzche, and Marx to adopt the "Ethos of Redemption" (Theology of the Body) to combat the "masters of suspicion" already mentioned. He does not settle for the excuse, 'we are only human flesh'. That is why, in Redemptor Hominis, he deals with the truth of redemption in a human dimension and in a divine dimension--as Christ united both in himself:
We can and must immediately reach and display to the world our
unity in proclaiming the mystery of Christ, in revealing the divine
dimension and also the human dimension of the Redemption, and in
struggling with unwearying perseverance for the dignity that each human
being has reached and can continually reach in Christ, namely the dignity
of both the grace of divine adoption and the inner truth of humanity, a
truth which—if in the common awareness of the modern world it has been
given such fundamental importance—for us is still clearer in the light of
the reality that is Jesus Christ. (Redemptor Hominis ch.11)
It is not enough for humanity to come to some greater appreciation of itself as reasonable, industrious, etc. Rather, man has to be raised to his crucial relationship of covenant with God in Christ in order to fully grasp his dignity and worth--and in humility, to acknowledge God as its source and summit. Revolutions like the Enlightenment and Marxism drastically fall short of this call. So too does any technological advancement invented by man that promises to alleviate suffering for a time. JPII covers all of these substitutes for the Redeemer in his writings. Furhtermore, he notes that the need for a redeemer is written on the human conscience ever since the first sin.
The need for a redeemer is clearly seen throughout Scripture. Especially one who could definitively reunite God and man. If we look at the depictions of bloodshed in the earliest recorded Judeo-Christian history, we see that Abel ends up to be the first martyr and victim of familial violence. His death is mentioned in the Letter to the Hebrews "the blood of Christ speaks more eloquently than that of Abel"(Heb 12), and is directly compared to the redemptive blood of the Son of God whose life continued beyond death. Just as the message of the Redeemer 'speaks' to JPII, so too does Abel's blood 'speak' of a need for the Redeemer. Abel's blood, like every innocent victim of violence since himself, demands an answer from God. Even God says, soon after the murder of Abel by Cain, "Your brother's blood cries out to me from the ground!" (Gen 4). So too, the blood of the martyrs 'speaks' of the past, present, and future need for the blood of the Redeemer to restore life to man's mortality, and JPII captures the pulse of this communication in Redemptoris Missio (ch. 1):
Although participated forms of mediation of different kinds and
degrees are not excluded, they acquire meaning and value
only from Christ's own mediation
That is to say, that the blood of the martyrs does not suffice as redemptive unless Christ is raised from the dead! Abel's blood would have no answer from God had not Christ poured out his blood on the cross. Not only die, but rise to see his blood forever re-gain its vitality and 'speak eloquently'. This is exactly what JPII is writing about in his reference to the Eucharist as the living body and blood, or lifeblood, of the Redeemer. The dignity and value of man, paid for by the priceless and living blood of Christ, is nearly ineffable. In the Eucharist too, this price remains with man as enduring proof of his redemption. None can say that he is far from them or distant from one's suffering, dying, or loneliness. The answer to all of man's wounds is in the redemption!
That is why, as the first Slavic pope, Karol Wojtyla so strongly identified with the Redeemer. He had experienced firsthand, the extent to which Christ had taken on the human condition and with Divine Mercy raised it up to God. He explains (Redemptor Hominis ch.1):
In its penetrating analysis of "the modern world", the Second Vatican
Council reached that most important point of the visible world that is
man, by penetrating like Christ the depth of human consciousness and by
making contact with the inward mystery of man, which in Biblical and
non-Biblical language is expressed by the word "heart". Christ, the
Redeemer of the world, is the one who penetrated in a unique
unrepeatable way into the mystery of man and entered his "heart"
JPII goes as far as saying that Vatican II was an initiative of the Redeemer to more thoroughly influence wayward man! How great an emphasis he places on redemption, as to afford the council a special mission and goal toward this end of proving to man that Jesus loved him to death and beyond. Redemptor Hominis, as his first encyclical, effectively communicates JPII's burden for accurately instituting the teachings of the council and to bring the Church into year of Jubilee, 2000. Wojtyla lived to see that day, having done exactly what he proposed in the opening years of his reign.
Update "Unequal Exchange":
It is not as though the life of the Redeemer for our life is an equally valid and contractual exchange, no it is completely gratuitous. Pope BXVI says, "The mystery of the Covenant expresses this relationship between God who calls man with his word, and man who responds, albeit making clear that it is not a matter of a meeting of two peers; what we call the Old and New Covenant is not a
contract between two equal parties, but a pure gift of God." (Verbum Domini #22)