Modern Christians have an advantage ancient Jews and Christians did not. Our Bibles are divided into helpful verses and chapters. We can say "Mark 15:34" or "Psalm 22:1", and have anyone we're talking to turn to that very place in seconds. But this is a recent invention. In Jesus' day, the way to call a passage to mind was to quote it.
On the cross, Jesus did exactly that. He cried aloud "Eloi, Eloi, lama sabachthani". This draws attention to one of the more amazing Messianic prophecies in the Old Testament: Psalm 22.
Psalm 22 so obviously matches Christ's crucifixion that if you did not know it was written centuries before, you might well assume it was written about it. 15 points compel us to believe this Psalm is intended to be a prophecy about Jesus:
1. He was forsaken while others are saved (v1-6).
"My God, My God, why have You forsaken Me? Why are You so far from helping Me, And from the words of My groaning? O My God, I cry in the daytime, but You do not hear; And in the night season, and am not silent. But You are holy, Enthroned in the praises of Israel. Our fathers trusted in You; They trusted, and You delivered them. They cried to You, and were delivered; They trusted in You, and were not ashamed. But I am a worm, and no man; A reproach of men, and despised by the people."
The beginning of the passage is the one cited by Christ on the cross, drawing it to our attention. It continues far beyond what Jesus cited, highlighting how God delivered the righteous people who trusted in Him. But Jesus was not delivered. Though He was more righteous than any of them, He endured the fullness of God's curse. Note how God's absence is not used as an excuse for slander. God's Holiness is affirmed very strongly. There is a reason God has forsaken the Messiah.
2. He was rejected by the people (v6-8).
"But I am a worm, and no man; A reproach of men, and despised by the people. All those who see Me ridicule Me; They shoot out the lip, they shake the head, saying, “He trusted in the Lord, let Him rescue Him; Let Him deliver Him, since He delights in Him!”"
Anyone who has read the Gospels is familiar with this occurrence. It's exactly what people were saying at the foot of the cross.
3. He was always faithful, even from the womb (v9-10).
"But You are He who took Me out of the womb; You made Me trust while on My mother’s breasts. I was cast upon You from birth. From My mother’s womb You have been My God."
How much does a suckling infant know about God? While it is possible we have severely underestimated the wisdom of a child, it does not seem to be a regular occurrence for any child to know how to trust God. Yet Jesus had to be perfect from the moment He was conceived.
4. He was opposed by powerful people (v12-13).
"Many bulls have surrounded Me; Strong bulls of Bashan have encircled Me. They gape at Me with their mouths, Like a raging and roaring lion."
Without going into too much depth, we are not talking about literal bulls here. Rather, "bulls of Bashan" is a metaphor, referring to powerful, prideful and oppressive people. Amos 4:1 similarly rebukes and warns such "bulls of Bashan" for their oppressive ways. Jesus was certainly surrounded by such bulls of Bashan. The Pharisees, Sadducees and even the Romans had all conspired to put Him on that cross, and were no doubt present to revel in their handiwork.
5. He was "poured out like water" (v14).
Here we're starting to dive into the medical stuff. Jesus was not just poured out like water, but when He was stabbed, His body actually spilled out blood and water (John 19:34).
6. He was dehydrated (v14-15).
"I am poured out like water, And all My bones are out of joint; My heart is like wax; It has melted within Me. My strength is dried up like a potsherd, And My tongue clings to My jaws; You have brought Me to the dust of death."
Dehydration is a natural effect of blood loss. With all the blood Jesus lost just leading up to the cross, let alone the blood that would have continued to spill out from His wounds as He hung there, Jesus would have been extremely thirsty (which we know He was, because He explicitly said so).
7. He was killed (v15).
"My strength is dried up like a potsherd, And My tongue clings to My jaws; You have brought Me to the dust of death."
Jesus died. Next.
8. His hands and feet were pierced (v16).
"For dogs have surrounded Me; The congregation of the wicked has enclosed Me. They pierced My hands and My feet;"
This is the point most often attacked by dissenters. It is claimed that this is actually a mistranslation. It's not "they pierced my hands and my feet", but "like lions, they are at my hands and my feet". It is claimed that Christians deliberately altered the text to make it sound more like Jesus.
The first problem with this objection is that the sceptic using it flat out admits that with this rendering, it sounds like Jesus is being talked about here. The second problem is that if we assume the translation error is, indeed, a translation error, what is a lion going to do to your hands and feet? It's going to pierce them. All this objection does is slightly alter the point to make it less obvious, weakening, but not refuting, one point out of 15. Even this would merely reduce us to 14 points and a weak point, which is still rather strong.
The third problem is that there is a threefold witness to "they pierced my hands and feet" being the correct rendering. First, there are 12 Masoretic manuscripts that do say pierced. This is admittedly weak, but they do exist. The second is that the Dead Sea Scrolls included Psalm 22, and favour the pierced rendering. The third is that the Septuagint, a Greek translation of the Hebrew Bible that existed before Christ, also rendered the verse "pierced". Thus, we can be reasonably confident that this is the correct rendering.
9. His bones were dislocated (v14, 17).
"I am poured out like water, And all My bones are out of joint; My heart is like wax; It has melted within Me. (...) I can count all My bones. They look and stare at Me."
Crucifixion was preceded by beatings. These beatings were carried out with horrible whips, which features shards of glass and things like that, so that after making contact with the skin, they would pull back skin and muscle, exposing bone. Furthermore, the process of hanging on the cross would pull on the victim. Jesus' bones were certainly dislocated, and many of them exposed.
10. He was publicly executed in front of a crowd of haters (v16-17).
"For dogs have surrounded Me; The congregation of the wicked has enclosed Me. They pierced My hands and My feet; I can count all My bones. They look and stare at Me."
The crucifixion was a very public event, and many people who hated Jesus showed up to see it. There were some righteous among the crowd, such as Jesus' mother, whom He entrusted to John, who was standing right next to her at the foot of the cross. But most of the people who surrounded Him, even the thieves on the crosses right next to Him, mocked Him.
11. The crowd bartered for His clothes (v18).
This is one element of the story most modern people doubt. Who would want bloody clothes, after all? But we're thinking about this in a modern context. People back then didn't have the benefit of popping into town and coming home with a brand new wardrobe. They usually had to make their own clothes, even out of materials they produced themselves. Thus, it was quicker, easier, and cheaper, to just buy the clothes of a crucifixion victim. We know that this happened to Jesus (Matthew 27:35).
12. He was ultimately rescued (v21).
"Save Me from the lion’s mouth And from the horns of the wild oxen! You have answered Me."
To be forsaken and to be answered don't exactly line up, neither does to be brought to the dust of death, and yet to be answered. But Jesus, as we know, rose. God didn't turn His back forever, but only for the duration of the execution. When Jesus committed His spirit to God and bowed His head, he announced "it is finished", and then on the third day, He got up and walked out of His tomb.
13. This story gets spread to everyone (v27, 31).
"All the ends of the world Shall remember and turn to the Lord, And all the families of the nations Shall worship before You. (...) They will come and declare His righteousness to a people who will be born, That He has done this."
The account of Jesus is so widespread that even hostile religions mention it. The Jews passed down alternative explanations, the Muslims claim it never happened, Christians of course profess its truth, and this story has gone out to all ends of the Earth, and all the families of the nations have some knowledge of it. Of course, this is still being fulfilled, and I don't believe the end times will trigger until it has been completely fulfilled, but great progress has been made.
14. Gentiles worship God because of this (v27).
"All the ends of the world Shall remember and turn to the Lord, And all the families of the nations Shall worship before You."
Of all the Jews in history, who has caused gentiles to worship God more than Jesus? Because of Jesus, I worship God. Because of Jesus, you may also worship God. The Lord God of Israel, while He was previously worshipped mainly by Israel, is worshipped in almost all nations to some degree, all because of Jesus.
15. The effect of this carries on to the afterlife (v29).
"All the prosperous of the earth Shall eat and worship; All those who go down to the dust Shall bow before Him, Even he who cannot keep himself alive."
Every god in this world receives worship while its followers live, but Christ alone is worshipped by those who cannot keep themselves alive. More than that, all who go down to the dust bow before Him. Not just those who worshipped Him in life, but those who rebelled. Every false prophet, every deceitful philosopher, even the great kings of the past, bow before Jesus in the afterlife.
Maybe one or two of these points could be a coincidence. But all of them? Not a chance. Psalm 22 so clearly describes Jesus that one could theoretically cite it to an uninformed person and have them say "that's about Jesus". Isn't it encouraging to know we have such a powerful God that He could give us this powerful testimony even before these things came to pass?