Irenaeus repeatedly teaches in his writings that Satan was bound at the First Advent.
[W]hen He spoke of the devil as strong, not absolutely so, but as in comparison with us, the Lord showed Himself under every aspect and truly to be the strong man, saying that one can in no other way “spoil the goods of a strong man, if he do not first bind the strong man himself, and then he will spoil his house.” Now we were the vessels and the house of this [strong man] when we were in a state of apostasy; for he put us to whatever use he pleased, and the unclean spirit dwelt within us. For he was not strong, as opposed to Him who bound him, and spoiled his house; but as against those persons who were his tools, inasmuch as he caused their thought to wander away from God: these did the Lord snatch from his grasp. As also Jeremiah declares, “The Lord hath redeemed Jacob, and has snatched him from the hand of him that was stronger than he.” If, then, he had not pointed out Him who binds and spoils his goods, but had merely spoken of him as being strong, the strong man should have been unconquered (Against Heresies Book 4, Chapter 8).
The continuous message from Irenaeus is that Satan is a defeated foe that has been stripped of his previous power and influence through his spiritual binding in spiritual chains. It is equally that the redeemed have been fully rescued from the clutches and influence of the wicked one. As a result, he has no ability to stop the advance of the kingdom of God from being completed, though he tries with all his might.
This teaching is consistent with the inspired text where the Lord identifies the casting out of devils, and the resulting liberating of souls, with the actual binding of the strong man. Jesus in turn presents this as proof that Satan is curbed through the presence and victorious function of the kingdom of God. Christ was specifically referring to Satan here (the strong man) and his demonic kingdom, and expressly connects his binding with the manifestation of the kingdom of God during His earthly ministry. The subjugating of devils was proof of the spiritual restraint of the evil one. Satan could not prevent this. Satan could not overcome those who had been rescued by Christ.
The devil was subject to the purposes of God and hurt by the spiritual advance of the kingdom of God. This kingdom is still alive and active today. Souls are still being marvelously delivered from the power of Satan. The binding of the strong man continues today wherever the Gospel prevails. The binding of Satan and the spoiling of his house were globalized to relate to mankind.
[T]he law does indeed declare the Word of God from the Father; and the apostate angel of God is destroyed by its voice, being exposed in his true colours, and vanquished by the Son of man keeping the commandment of God. For as in the beginning he enticed man to transgress his Maker’s law, and thereby got him into his power; yet his power consists in transgression and apostasy, and with these he bound man [to himself]; so again, on the other hand, it was necessary that through man himself he should, when conquered, be bound with the same chains with which he had bound man, in order that man, being set free, might return to his Lord, leaving to him (Satan) those bonds by which he himself had been fettered, that is, sin. For when Satan is bound, man is set free; since “none can enter a strong man’s house and spoil his goods, unless he first bind the strong man himself.” The Lord therefore exposes him as speaking contrary to the word of that God who made all things, and subdues him by means of the commandment. Now the law is the commandment of God. The Man proves him to be a fugitive from and a transgressor of the law, an apostate also from God. After [the Man had done this], the Word bound him securely as a fugitive from Himself, and made spoil of his goods – namely, those men whom he held in bondage, and whom he unjustly used for his own purposes. And justly indeed is he led captive, who had led men unjustly into bondage; while man, who had been led captive in times past, was rescued from the grasp of his possessor (Against Heresies Book 5, Chapter 21, 3).
Irenaeus concludes by stressing the grounds of Satan’s defeat – the perfect obedience of Christ as our substitute in fulfilling the Law. He shows: through Christ’s perfect submission to the Law, through His substitutionary work, He totally removed our condemnation. As the expressed manifestation of the Word and every promise contained within it, Christ came to destroy the works of darkness. A lot of Christians overlook the fact that Calvary would have been ineffective if our Lord hadn’t been a perfect sinless sacrifice. Christ had to meet every demand of the Law. No ordinary mortal man could achieve that. That is why the Lord had to take upon Himself human form and fulfil every minute detail of the Law on his behalf. In doing so He destroyed the claim that Satan had over all mankind.
He explains that the chains that weighed down the people of God of all nations since the Fall have now been placed upon Satan thus curtailing or binding his power. Gentiles have been liberated by the substitutionary work of Christ in living the life they could never live and paying the debt they could never pay. In life and death Jesus was that perfect representative. Those who would put their personal trust in Christ and His finished work at the cross enter into the spiritual benefits of what He secured for them through Calvary. By faith they appropriate victory over sin, death and eternal damnation. By faith they overcome the devil. Whilst man cannot overcome the devil on his own merits, Satan is defeated through our federal head – Jesus Christ – who took the place and penalty of the believer at the cross.
Obviously, the bonds Irenaeus speaks of are not physical chains, clearly, this is not a literal physical prison. Satan’s control was demolished everywhere the kingdom triumphed - in the case of individuals, nations and peoples.
Then in the Gospel, casting down the apostasy by means of these expressions, He did both overcome the strong man by His Father's voice, and He acknowledges the commandment of the law to express His own sentiments, when He says, You shall not tempt the Lord your God. For He did not confound the adversary by the saying of any other, but by that belonging to His own Father, and thus overcame the strong man (Against Heresies Book 5, Chapter 22, 1).
Every single reference to the binding of Satan here relates to the defeat of Satan through Christ’s earthly assignment and the taking back of what Adam surrendered in the Fall. Satan is therefore already “overcome” according to Irenaeus.