Unfortunately, Protestant theology regarding Christ's Passion is in most cases essentially a fusion of ancient Christian heresies with pagan understanding of sacrifice, which leaves the Resurrection of Christ as a short of add on. For Orthodox Christianity if anything the Resurrection is of more importance than the Crucifixion, as it is by the Resurrection that man is saved from death, for Adam is brought up from death, where he fell, back to his Creator. Fundamentally without the Resurrection there is no salvation. In my opinion one of the best witnesses of Orthodox Theology regarding salvation is to be found in the anaphora of St Basil,
...Having made man by taking dust from the earth, and having honored him with Your own image, O God, You placed him in a garden of delight, promising him eternal life and the enjoyment of everlasting blessings in the observance of Your commandments. But when he disobeyed You, the true God who had created him, and was led astray by the deception of the serpent becoming subject to death through his own transgressions, You, O God, in Your righteous judgment, expelled him from paradise into this world, returning him to the earth from which he was taken, yet providing for him the salvation of regeneration in Your Christ. For You did not forever reject Your creature whom You made, O Good One, nor did You forget the work of Your hands, but because of Your tender compassion, You visited him in various ways: You sent forth prophets; You performed mighty works by Your saints who in every generation have pleased You. You spoke to us by the mouth of Your servants the prophets, announcing to us the salvation which was to come; You gave us the law to help us; You appointed angels as guardians. And when the fullness of time had come, You spoke to us through Your Son Himself, through whom You created the ages. He, being the splendor of Your glory and the image of Your being, upholding all things by the word of His power, thought it not robbery to be equal with You, God and Father. But, being God before all ages, He appeared on earth and lived with humankind. Becoming incarnate from a holy Virgin, He emptied Himself, taking the form of a servant, conforming to the body of our lowliness, that He might change us in the likeness of the image of His glory. For, since through man sin came into the world and through sin death, it pleased Your only begotten Son, who is in Your bosom, God and Father, born of a woman, the holy Theotokos and ever virgin Mary; born under the law, to condemn sin in His flesh, so that those who died in Adam may be brought to life in Him, Your Christ. He lived in this world, and gave us precepts of salvation. Releasing us from the delusions of idolatry, He guided us to the sure knowledge of You, the true God and Father. He acquired us for Himself, as His chosen people, a royal priesthood, a holy nation. Having cleansed us by water and sanctified us with the Holy Spirit, He gave Himself as ransom to death in which we were held captive, sold under sin. Descending into Hades through the cross, that He might fill all things with Himself, He loosed the bonds of death. He rose on the third day, having opened a path for all flesh to the resurrection from the dead, since it was not possible that the Author of life would be dominated by corruption. So He became the first fruits of those who have fallen asleep, the first born of the dead, that He might be Himself the first in all things.... -St Basil the Great (translation from Goarch.org website) [emphasis mine]
The importance of the Resurrection can also be found in the homily of St John Chrysostom
Enjoy ye all the feast of faith: Receive ye all the riches of loving-kindness. let no one bewail his poverty, for the universal kingdom has been revealed. Let no one weep for his iniquities, for pardon has shown forth from the grave. Let no one fear death, for the Savior’s death has set us free. He that was held prisoner of it has annihilated it. By descending into Hell, He made Hell captive. He embittered it when it tasted of His flesh. And Isaiah, foretelling this, did cry: Hell, said he, was embittered, when it encountered Thee in the lower regions. It was embittered, for it was abolished. It was embittered, for it was mocked. It was embittered, for it was slain. It was embittered, for it was overthrown. It was embittered, for it was fettered in chains. It took a body, and met God face to face. It took earth, and encountered Heaven. It took that which was seen, and fell upon the unseen.
O Death, where is your sting? O Hell, where is your victory? Christ is risen, and you are overthrown. Christ is risen, and the demons are fallen. Christ is risen, and the angels rejoice. Christ is risen, and life reigns. Christ is risen, and not one dead remains in the grave. For Christ, being risen from the dead, is become the first fruits of those who have fallen asleep. To Him be glory and dominion unto ages of ages. Amen. -Translation O.C.A.
Further in the Scriptures the Resurrection is of paramount importance, in the Acts of the Apostles it is the Resurrection which is proclaimed for example 'with great power gave the apostles witness of the resurrection of the Lord Jesus: and great grace was upon them all.' , indeed St Paul said before the Sanhedrin 'of the hope and resurrection of the dead I am called in question.'
Perhaps though the most compelling argument against what he says is that by Saint Paul in 1 Corinthians,
Brethren, I declare unto you the gospel which I preached unto you, which also ye have received, and wherein ye stand; By which also ye are saved, if ye keep in memory what I preached unto you, unless ye have believed in vain. For I delivered unto you first of all that which I also received, how that Christ died for our sins according to the scriptures; And that he was buried, and that he rose again the third day according to the scriptures: And that he was seen of Cephas, then of the twelve: After that, he was seen of above five hundred brethren at once; of whom the greater part remain unto this present, but some are fallen asleep. After that, he was seen of James; then of all the apostles. And last of all he was seen of me also, as of one born out of due time. For I am the least of the apostles, that am not meet to be called an apostle, because I persecuted the church of God. But by the grace of God I am what I am: and his grace which was bestowed upon me was not in vain; but I laboured more abundantly than they all: yet not I, but the grace of God which was with me. Therefore whether it were I or they, so we preach, and so ye believed. Now if Christ be preached that he rose from the dead, how say some among you that there is no resurrection of the dead? But if there be no resurrection of the dead, then is Christ not risen: And if Christ be not risen, then is our preaching vain, and your faith is also vain. Yea, and we are found false witnesses of God; because we have testified of God that he raised up Christ: whom he raised not up, if so be that the dead rise not. For if the dead rise not, then is not Christ raised: And if Christ be not raised, your faith is vain; ye are yet in your sins. Then they also which are fallen asleep in Christ are perished. If in this life only we have hope in Christ, we are of all men most miserable. But now is Christ risen from the dead, and become the firstfruits of them that slept. For since by man came death, by man came also the resurrection of the dead. For as in Adam all die, even so in Christ shall all be made alive. - K.J.V. [emphasis mine]
P.S. I am writing this after 11 P.M. on a day upon which I feel so tired that feel as as though I have never really woken up, so please forgive an lack of coherence and the rather haphazard manner in which this post ins constructed.