Did Christ have to rise? No, God could have chosen other methods to show us His justice and love. However, for many reasons it was fitting that Jesus should rise bodily and present Himself to His disciples and other believers.
St. Thomas Aquinas presents us with five reasons that the resurrection was fitting. Let’s examine his teaching. St. Thomas’ writing is presented bold, black italics, while my inferior comments appear in plain red text. The teaching is drawn from the Summa Theologiae III, Q. 53, Art. 1.
It behooved Christ to rise again, for five reasons.
First of all; for the commendation of Divine Justice, to which it belongs to exalt them who humble themselves for God’s sake, according to Luke 1:52: “He hath put down the mighty from their seat, and hath exalted the humble.” Consequently, because Christ humbled Himself even to the death of the Cross, from love and obedience to God, it behooved Him to be uplifted by God to a glorious resurrection; hence it is said in His Person (Psalm 138:2): “Thou hast known,” i.e. approved, “my sitting down,” i.e. My humiliation and Passion, “and my rising up,” i.e. My glorification in the resurrection; as the gloss expounds.
God has put His justice in our hearts and it is something for which every human being ultimately longs. While the object of our sense of justice may sometimes be wrong (for some perceive the details of justice wrongly, seeing a grievance where there is none or failing to see injustice where it exists), the longing for justice is hard-wired in our soul.
That acts of murder, theft, violence, injustice to the poor and innocent, and so forth might go unaddressed offends against our deepest sensibilities. God, who put this sense of justice in us—a metaphysical concept that seems wholly lacking in animals—confirms His own justice in Jesus rising from the dead.
Although God’s justice may at times seem delayed, it will come. In the final judgement, all will be set right; hidden deeds and crimes will be disclosed and prosecuted and the truth of God will stand forth vindicated.
This should both console and sober us. For if God’s justice tarries, it is only so as to give us time to repent. There is a day of final justice appointed for this world. Christ’s resurrection proves the world wrong (Jn 16:8-9) and vindicates God’s truth. It sets before us God’s justice so that we understand that nothing unavenged will ultimately remain.
Secondly, for our instruction in the faith, since our belief in Christ’s Godhead is confirmed by His rising again, because, according to 2 Corinthians 13:4, “although He was crucified through weakness, yet He liveth by the power of God.” And therefore it is written (1 Corinthians 15:14): “If Christ be not risen again, then is our preaching vain, and our faith is also vain”: and (Psalm 29:10): “What profit is there in my blood?” that is, in the shedding of My blood, “while I go down,” as by various degrees of evils, “into corruption”? As though He were to answer: “None. ‘For if I do not at once rise again but My body be corrupted, I shall preach to no one, I shall gain no one,’” as the gloss expounds.
The resurrection of Jesus Christ from the dead is the most fundamental of Christian dogmas. If this be not true, then let’s just call the rest of the whole thing off! However, since Christ is raised from the dead, all of what He taught is confirmed and worthy of our faith. He who said I AM the truth (i.e., I am truth itself and all that I have spoken to you is thereby true) has this confirmed by His resurrection. The truth of the resurrection confirms His divinity and the veracity of everything else He proclaimed and announced. Thus the resurrection is fitting for instruction in all the truths of faith.
Thirdly, for the raising of our hope, since through seeing Christ, who is our head, rise again, we hope that we likewise shall rise again. Hence it is written (1 Corinthians 15:12): “Now if Christ be preached that He rose from the dead, how do some among you say, that there is no resurrection of the dead?” And (Job 19:25-27): “I know,” that is with certainty of faith, “that my Redeemer,” i.e., Christ, “liveth,” having risen from the dead; “and” therefore “in the last day I shall rise out of the earth … this my hope is laid up in my bosom.”
Hope is the confident expectation of God’s help in attaining eternal life with Him. What can give greater confidence than to see Christ, who was so brutally struck down, stand victorious over sin and death? Whatever we endure in this life of our own crosses, we can confidently expect to stand victorious over them as well. We shall have the victory in Christ Jesus, our Lord. Indeed, even now, we know that in all things God works for the good of those who love him, who have been called according to his purpose (Rom 8:28).
Fourthly, to set in order the lives of the faithful: according to Romans 6:4: “As Christ is risen from the dead by the glory of the Father, so we also may walk in newness of life”: and further on; “Christ rising from the dead dieth now no more; so do you also reckon that you are dead to sin, but alive to God.”
In His resurrection, Jesus shows not only His divinity, but also a transformed humanity. While in His sinlessness prior to the resurrection He already showed forth a life free from disorder, in His resurrected humanity He shows this even more gloriously. He manifests qualities such as agility, subtlety, and clarity. (I have written more about that here.)
Some of these last qualities will be known by us only when our bodies rise, perfected and glorified. Even now, though, the Lord, by the grace of His passion, death, and resurrection, has purchased for us a new life—a life transformed and increasingly free from sin, sorrow, regret, anger, greed, lust, and all forms of negativity. To be a new creation in Christ is to be more confident, serene, joyful, virtuous, and chaste. It is to live a life that is orderly and properly directed to our noble and glorious end: life with God forever.
Jesus, in his resurrection, manifests this capacity for us to walk in newness of life.
Fifthly, in order to complete the work of our salvation: because, just as for this reason did He endure evil things in dying that He might deliver us from evil, so was He glorified in rising again in order to advance us towards good things; according to Romans 4:25: “He was delivered up for our sins, and rose again for our justification.”
Thus it is one thing to be forgiven of our sins, but God does more by healing us increasingly of sin’s effects. The chief effect of sin was our alienation from the Father, but in Jesus, man returned to God. To be justified is to be in a right relationship with the Father, and that relationship, like all relationships, changes us. In Jesus, risen from the dead, we are restored to the Father and rightly called sons of God because we are made members of the risen and glorified Body of Christ, who is the Son of God. In our risen and ascended Christ and as members of His Body, we sit at the Father’s right in glory, provided that we do not sever our relationship with Christ by serious sin.