St. Thomas Aquinas proposes three answers to the question. Let’s consider them, with particular emphasis on the third.
I. To Identify with Fallen Sinners – St Thomas said, As Christ became accursed of the cross for us, so for our salvation He was crucified as a guilty one among the guilty (Comm. xxxiii in Matth.) (Summa Theologica III, Q 46, Art. 11).
In other words, Jesus bore our guilt and our shame, though He Himself was sinless (see 1 Peter 2:24 and Isaiah 53:4). He was assigned a grave with the wicked, and with the rich in his death, though he had done no violence, nor was any deceit in his mouth (Is 53:9). And thus Christ took up and endured the punishments we deserved.
We are all sinners and thieves. How are we thieves? One who takes what belongs to another is a thief, but so also is one a thief who uses what he received from another in a way contrary to his will. In this way we are all thieves, for we have used the things of God in ways contrary to what He wants.
Consider our bodies, which belong to God (see 1 Cor 6:19-20). How often do we use them in ways contrary to what God, the true owner of our bodies, wants? We often use our bodies to sin. We use the gift of speech to speak words of malice and deceit rather than those of truth and encouragement. We allow our eyes to look upon things that violate what God would have us see. We use our ears to listen to gossip, hatred, and impurity. Using our bodies in ways that oppose what the true owner wants is a form of theft.
So we are all thieves. And yet Christ, who never stole and never sinned, is willing to be seen and counted among us! The book of Hebrews says that He is not ashamed to call us brethren. Yes, He is identified with sinners and thieves like us.
II. To Image the Final Separation – Jesus indicates that there is a great separation between those on his right (the sheep) and those on his left (the goats) on the Day of Judgment (see Matt 25:41ff). St. Thomas said,
… [A]s Pope Leo observes (Serm. iv de Passione): “Two thieves were crucified, one on His right hand and one on His left, to set forth by the very appearance of the gibbet that separation of all men which shall be made in His hour of judgment.” And Augustine on John 7:36: “The very cross, if thou mark it well, was a judgment-seat: for the judge being set in the midst, the one who believed was delivered, the other who mocked Him was condemned. Already He has signified what He shall do to the quick and the dead; some He will set on His right, others on His left hand.” … because of the cleavage between believers and unbelievers, the multitude is divided into right and left, those on the right being saved by the justification of faith (Summa Theologica III, Q 46, Art. 11).
Thus this moment indicates or pictures the final judgment, when Christ, seated on His throne as Judge of the World and Lord of all, will have some to His right and others to His left. Some will be the sheep and others the goats; some will be the wise virgins and others the foolish ones. Those on His right will hear, Come, you who are blessed by my Father, inherit the kingdom prepared for you from the foundation of the world (Matt 25:34). Those on his left will hear, Depart from me, you cursed, into the eternal fire prepared for the devil and his angels (Matt 25:41).
III. To Insist on Freeing Suffering – Christ insisted that true disciples would be distinguished by their willingness to carry the cross. Though God originally offered paradise, Adam and Eve’s (our) rejection of it and insistence upon living in Paradise Lost, means that the Lord must insist upon the cross (suffering) as the only remedy for our salvation. St. Thomas wrote,
Bede says on Mark 15:27: “The thieves crucified with our Lord denote those who, believing in and confessing Christ, either endure the conflict of martyrdom or keep the institutes of stricter observance. But those who do [this] for the sake of everlasting glory are denoted by the faith of the thief on the right; while others who do so for the sake of human applause copy the mind and behavior of the one on the left.” (Summa Theologica III, Q 46, Art. 11).
Yes, to follow Christ involves suffering and rejection. It also involves stricter observance, which postpones certain passing pleasures in order to inherit lasting ones, which rejects apparent goods in order to receive true goods. Some are willing to endure this, while others are not.
The good thief accepted that he was suffering as he deserved, asking only to suffer with Christ. He accepted the cross and was willing to be identified with the true Christ—crucified Christ. He was willing to endure this as the way to paradise.
The bad thief wanted to be taken down. He wanted nothing to do with the cross. He thought as human beings do, not as God demanded. Like the scoffers beneath the cross, he demanded that the Messiah come down rather than endure it, that the Messiah eliminate the cross rather than insist upon it. In so doing, the bad thief sought human applause rather than God’s approval. And so the bad thief suffered in vain.
Jesus said, Anyone who does not take up his cross and follow Me is not worthy of Me (Matt 10:38). Whoever wants to be my disciple must deny himself and take up his cross and follow me (Matt 16:24). St. Paul said, … we preach Christ crucified, a stumbling block to Jews and foolishness to Gentiles, but to those who are called, both Jews and Greeks, Christ the power of God and the wisdom of God (1 Cor 1:23-25). He also lamented, For, as I have often told you before and now tell you again even with tears, many live as enemies of the cross of Christ. Their destiny is destruction, their god is their stomach, and their glory is in their shame. Their mind is set on earthly things (Phil 3:18-19).
The men on either side of the Lord are both thieves, but the similarity ends there. The one is not bad merely because he reviled Christ, but also because he refused the cross and the Messiah who embraced it. The other is good not only because he did not revile Christ, but also because he accepted his cross and was willing to suffer alongside Him. Christ’s cross (and his own sliver of it) was his spes unica (only hope), and he was willing to endure it.
The question for you is this: Which thief are you?
Many people today will have nothing to do with the cross, insisting that the Messiah would demand no such thing. Among them are many so-called Catholics. They scoff at the notion that God wants them to be anything but happy and content. Speak to them of any difficult thing such as turning away from sin or doing what is unpopular, and they will insist, “God wants me to be happy, doesn’t He?”
The latest “anti-cross” trend is physician-assisted suicide; it is a rejection of the cross. Yet those who support it insist on calling it “death with dignity” and/or the “right to die.” Among them, sadly, are many Christians, who should know better. They seem to think that suffering of this sort is meaningless.
Suffering is not meaningless. It brings wisdom, humility, perspective, strength, and trust. It reminds us of the passing quality of this world and prepares us to meet God.
To many, the cross must go; it shall not be. It is not far from the cry of the bad thief and the scoffers at the foot of the cross: “If you are the Messiah, come down from that cross!” But He will not be the messiah we expect. He does not seek human applause. He will be the true Messiah. Only the true Messiah can save us.
Which thief are you? Are you the one who accepts the cross and is willing to die outside the gate with Christ, or are you the one who insists that the cross must go?
Which one are you?