Because it is good.
If there were no eyewitnesses, there would be nothing to distinguish the Christ from other myths and Fairy Tales such as those of Greek Mythology. If there are eyewitnesses and they can relay similar accounts, then the historicity of the Christ becomes much more plausible and reasonable.
Jesus Christ
The ascension of Jesus to heaven concluded the earthly ministry of Jesus, allowing eyewitnesses to see both the risen Christ on earth and the victorious eternal Christ returning to heaven to minister at the right hand of the Father.
Their God, Jesus Christ and the Pope spring to mind
christ is a name that matches jesus
Catholics, being Christian believe that Jesus Christ is The Most Important. The pope is the successor of Peter, who Jesus Christ made head of his church.
Some individuals who were not eyewitnesses during Jesus' ministry include religious leaders outside of his immediate circle, those living in distant regions at the time, and many future generations who were not born yet.
I would suppose it was John the Baptizer. He introduced Christ Jesus to the people.
Jesus Christ
Muslims regard Jesus as an important prophet
Jesus Christ. But of course, many people are more interested in that stupid lady gaga.
John, Peter and James are eyewitnesses who walked and talked with Jesus and testify of Jesus in the flesh. Only an eyewitness can testify of Jesus in the flesh. Matthew and Mark probably also walked with Christ though there is some speculation on the actual authors of those books.
It is important because that is when our savior Jesus Christ was born. :)