The Holy Father concluded his catechesis on God as the Creator of "the things that are unseen" by speaking of the victory of Christ over the spirit of evil.
Our catechesis on God, the Creator of the things "that are unseen", have brought fresh light and strength to our faith concerning the truth about the evil one, or Satan; he is certainly not willed by God, who is supreme Love and Holiness, and whose wise and strong Providence knows how to guide our existence to victory over the prince of darkness. The Church's faith, in fact, teaches us that the power of Satan is not infinite. He is only a creature - powerful, in that he is pure spirit, but nevertheless always a creature, with the limits proper to creatures, subordinated to the will and dominion of God. If Satan is at work in the world because of his hatred of God and of his Kingdom, this is permitted by Divine Providence which directs the history of man and of the world with power and goodness (fortiter et suaviter). It is certainly true that Satan's action causes much damage, both of a spiritual kind and also indirectly of a material kind, to individuals and to society, but he is not able ultimately to neutralize the definitive end towards which man and all creation tend. the Good. He cannot block the construction of the Kingdom of God, in which at the end there will be the full realization of the righteousness and the love of the Father for the creatures who are eternally "predestined" in Jesus Christ, his Son and Word. Indeed, we can say with St. Paul that the work of the evil one cooperates for the good (cf. Rom 8:28) and that it helps to build up the glory of the "chosen" ones (cf. 2 Tim 2:10).
Thus, the whole history of humanity can be considered as serving total salvation which means the victory of Christ over the "prince of this world" (Jn 12:31; 14:30; 16:11). "You shall bow down only before the Lord your God, you shall adore him alone" (Lk 4:8), says Christ eternally to Satan. At a dramatic moment of his ministry, when he was openly accused of casting out the demons because of his alliance with Beelzebul, the chief of the demons, Jesus replied with these words that are at once severe and comforting. "Every kingdom that is divided falls into ruins, and no city or family that is divided can stand upright. Now if Satan drives out Satan, then he is divided in himself. How then can his kingdom stand upright?... And if it is by the power of the Spirit of God that I cast out the demons, then it is certain that the Kingdom of God has come among you" (Mt 12:26-26, 28). "When a strong man, well armed, guards his palace, all his goods are secure. But if one stronger than he comes and overpowers him, he takes away the armour in which he trusted, and divides his spoils" (Lk 11:21-22). The words which Christ speaks about the tempter find their historical fulfillment in the cross and resurrection of the Redeemer. As we read in the Letter to the Hebrews, Christ became a sharer in human nature even to the cross "in order to reduce to powerlessness, by means of death, the one who has the power over death, that is, the devil... and thus to free those who... were held in slavery" (Heb 2:14-15). This is the great certainty of the Christian faith: "the prince of this world has been judged" (Jn 16:11); "the Son of God has appeared, in order to destroy the works of the devil" (1 Jn 3:8), as St. John bears witness. It is therefore the crucified and risen Christ who has revealed himself as that "stronger one" who has overpowered "the strong man", the devil, and has cast him down from his throne
The Church shares in Christ's victory over the devil, for Christ has given to his disciples the power to cast out demons (cf. Mt 10:1 and parallels; Mk 16:17). The Church uses this victorious power through faith in Christ and prayer (cf. Mk 9:29; Mt 17:19ff.), which in particular cases can take the form of exorcism.
It is to this historical phase of the victory of Christ that the announcement and the beginning of the final victory, the Parousia, belongs: this is the second and definitive coming of Christ at the close of history, and it is towards this that the life of the Christian is orientated. Even if it is true that earthly history continues to unfold under the influence of "that spirit who now is at work in rebellious men", as St. Paul says (Eph 2:2), believers know that they have been called to struggle for the definitive triumph of the Good. "for our battle is not against creatures made of blood and of flesh, but against the Principalities and Powers, against those who hold dominion over this world of darkness, against the spirits of evil that dwell in the heavenly places" (Eph 6:12).
4. As the end of the struggle gradually draws nearer, it becomes in a certain sense ever more violent, as Revelation, the last book of the New Testament, shows in a special emphasis (cf. Rev 12:7-9). But it is precisely this book that emphasizes the certainty that is given to us by all of divine Revelation, that the struggle will finish with the definitive victory of the good. In this victory, which is contained in anticipation in the paschal mystery of Christ, there will be the definitive fulfillment of the first announcement in the Book of Genesis, which is significantly called the Proto-Evangelium, when God admonishes the serpent: "I will put enmity between you and the woman" (Gen 3:15). In this definitive phase, God will complete the mystery of his fatherly Providence and "will set free from the power of darkness" those whom he has eternally "predestined in Christ" and will "bring them over into the kingdom of his beloved Son" (cf. Col 1:13-14). Then the Son will subject even the whole universe to the Father, so that "God may be all in all" (1 Cor 15:28).
Here we finish the catechesis on God as the Creator of "the things that are visible and invisible", which are united, in our structuring of the catechesis, with the truth about Divine Providence It is obvious to the eyes of the believer that the mystery of the beginning of the world and of history is joined indissolubly to the mystery of the end, in which the finality of all that has been created reaches fulfillment. The creed, which unites so many truths in such an organic manner, is truly the harmonious cathedral of the faith.
In a progressive and organic way, we have been able to admire, struck dumb with wonder, the great mystery of the intelligence and love of God, in his action of creation, directed to the cosmos, to the human person, and to the world of pure spirits. We have considered the Trinitarian origin of this action and its wise orientation towards the life of man who is truly the "image of God", called in his turn to rediscover fully his own dignity in the contemplation of the glory of God. We have been enlightened about one of the greatest problems that perturb man and characterize his search for truth: the problem of suffering and of evil. At the root, there is no mistaken or wicked decision by God, rather his choice - and in a certain manner the risk he has undertaken - of creating us free, in order to have us as friends. Evil too has been born of liberty. But God does not give up, and he predestines us with his transcendent wisdom to be his children in Christ, directing all with strength and sweetness, so that the good may not be overcome by evil.
We must now let ourselves be guided by Divine Revelation in our exploration of the other mysteries of our salvation. We have now received a truth which must be profoundly important for every Christian: that there are pure spirits, creatures of God, initially all good and then, through a choice of sin, irreducibly separated into angels of light and angels of darkness. And while the existence of the wicked angels requires of us that we be watchful so as not to yield to their empty promises, we are certain that the victorious power of Christ the Redeemer enfolds our lives, so that we ourselves may overcome these spirits. In this, we are powerfully helped by the good angels, messengers of God's love, to whom, taught by the tradition of the Church, we address our prayer: "Angel of God, who are my guardian, enlighten, guard, govern and guide me, who have been entrusted to you by the heavenly goodness. Amen".