Crucifixion became a common form of execution in the ancient world, mainly by the Carthaginians, Persians, Seleucids, and of course The Romans who used it until the fourth century, when emperor Constantine the Great abolished it.
The usual crucifixion began with the victim being flogged and severely beaten. He was then forced to carry or drag the crossbeam of the cross to the place of execution, where the upright post was already firmly fixed in the ground (see Cross Or Stake?). He was then bound or nailed to the crossbeam which was then raised up and attached to the post about 10 to 12 feet (3 or 4 meters) off the ground. The feet were then nailed to the post. The legs were then often broken with an iron bar.
The death of the victim, depending upon age and physical condition, would usually be the result of heart failure, suffocation or exhaustion - but rarely soon. In some cases, it could take days.
Jesus Christ was a strong, perfectly healthy young man when He was arrested That Fateful Night. And yet He died on the cross at Calvary (the "Place of The Skull," in photograph above) within one day. How is it that He died so unusually soon? Pilate himself was surprised when he found that Jesus was already dead (Mark 15:44).
The answer is found in John's record -
"Now it was the day of Preparation, and the next day was to be a special Sabbath [i.e. the annual Holy Day of the Passover, not the regular weekly Sabbath]. Because the Jews did not want the bodies left on the crosses during the Sabbath, they asked Pilate to have the legs broken and the bodies taken down. The soldiers therefore came and broke the legs of the first man who had been crucified with Jesus, and then those of the other. But when they came to Jesus and found that He was already dead, they did not break His legs. Instead, one of the soldiers pierced Jesus' side with a spear, bringing a sudden flow of blood and water." (John 19:31-34).
Many assume that the soldier speared The Body of Jesus after He was dead, but why would he do that? Sheer maliciousness could be one answer, but that would still leave the big question unanswered - Why then was Jesus already dead, before the other two men who were crucified with Him, and well before Pilate expected? Or, does the sentence describe, as numerous Biblical scholars now understand, that instead of killing Jesus by breaking His legs, the soldier killed Him with his spear? After all, the Scripture plainly says that "one of the soldiers pierced Jesus' side with a spear."
People who die of suffocation or heart failure unlikely do so with a "loud cry" as Jesus did (Mark 15:37) - they would not have sufficient air in their lungs to make the sound. But, people who have been suddenly stabbed do naturally cry out from the pain and the shock.
Also, dead people do not have the blood pressure to produce a "sudden flow of blood" as described in John 19:34 - but people who are still alive do.
In the Book of Revelation, the Apostle John describes the Prophecy of The Return Of Jesus Christ by saying -
"Look, He is coming in the clouds, and every eye will see Him, even those who pierced Him; and all the peoples of the earth will mourn because of Him." (Revelation 1:7)
There is special mention of that soldier, not because he needlessly speared the body of the dead Savior, but because that bloody stab wound was actually what killed Jesus Christ.
Throughout the Bible, Jesus Christ is referred to as "The Lamb of God" (John 1:29), which is a direct reference to the slaying of the Passover lamb - that was always done by its shed blood (Exodus 12:6-7). It is also very interesting to note that none of the lamb's bones were to be broken (Numbers 9:12).
Our salvation was made possible through the shed blood of The Savior, not by Him dying from exhaustion or a heart attack. That Roman soldier, almost certainly without realizing the tremendous significance of his brutal act, was the one who accomplished that requirement.
Fact Finder: Are we saved from the penalty for our sins by the actual shed blood of Jesus Christ?
1 Peter 1:19