Millions of people today believe that a man 2,000 years ago was raised from the dead and appeared to many people. They also believe he is in a "heavenly realm" where he can hear and sometimes answer their prayers. They believe he was the miraculously born "Son of God" who was empowered to perform miracles with super natural power.
Yet these same people will dismiss the miraculous claims made by other religions as ridiculous, improbable, and unbelievable. These same people say they accept the value of science and critical thinking yet they believe such extraordinary claims about something that supposedly happened once upon a time.
If someone told you they were abducted by aliens last night and taken to a spaceship for probing would you believe them? What if hundreds of people also told the same story? Many people are skeptical of such stories because the encounters are said to occur at night while they are in bed, there are different reports of what happened to them and what the aliens looked like, and lastly because most people have never experienced anything like this and have seen no evidence for the existence of UFOs or aliens.
If someone from work told you they have a Boeing AH-64 Apache Helicopter would you believe them? You know that such things exist but you also know they are military equipment, very expensive and it is very improbably that someone possesses one. What if someone told you they have an interstellar space craft? This is even more improbable because you don't even know if such things exist and even if they did exist how would this person have gained possession of one.
We are presented with claims everyday that we categorize differently based on our experience and judgments of probability. The more extraordinary the claim the more evidence we require to believe a claim. This prevents us from being gullible and looking stupid. It also prevents us from being deceived and having someone take advantage of us.
Rational thinking people use logic and experience to determine the probability of claims. We assume the world functioned in the past the same way it functions today. This prevents us from believing anything and everything. If someone says there were/are Vampires in Transylvania or Werewolves in London then we want to see evidence because we have no experience with such creatures today. If someone said that 2000 years ago their was a virgin born, son of a god that performed miracles and was raised from the dead as the savior of the world why should we believe it?
There were many ancient stories of virgin born, sons of god who performed miracles and were raised from the dead (Romulus, Heracles, etc). This was a time when people for the most part were uneducated, illiterate and superstitious. People believed a lot of crazy things and would often credit a god for things they couldn't explain. Is there then any good reason to believe the resurrection stories were true?
The four gospel accounts that found there way into the bible were written anonymously. The scholars that study them generally conclude that Mark was the first written and that the others borrowed from it. Which means they aren't independent. None of them were written by contemporaries but rather were written decades after the fact. They weren't even written by the language of Jesus or his disciples (i.e. Aramaic) rather they were written in Greek. You can see clear embellishment from Mark, to Matthew and Luke and then to John's gospel. On top of that they contradict one another in many areas. For these reasons the gospels are not considered reliable documents from a historical standpoint. And I haven't even started talking about the miraculous stories they contain yet. Miraculous birth, walking on water, using saliva to cure blindness, casting out demons to cure physical infirmities, raising the dead, zombies walking around Jerusalem, voices from heaven, etc. We do not experience any of these things today.
Aside from the anonymous gospels that found their way into the bible, there were some letters written by a guy called Paul. Paul claims to have been a Jewish pharisee that had a visionary experience of Jesus. This apparently was moving enough to make him a believer that Jesus had in fact been raised up to heaven next to the god of Israel. Paul went around preaching this and claims to have had interactions with Jesus' disciples. He writes letters to a few churches he had visited and preached in. Scholars today dispute several of Paul's letters as forgeries written by people claiming to have been Paul (e.g. Ephesians, Colossians, 1Timothy, 2 Timothy, Titus, and 2 Thessalonians are all disputed).
So is this really enough evidence to establish belief and thus dedicating one's life to the resurrection of Jesus? If you are going to commit your life, your time, your money, your beliefs and behavior to something, shouldn't you demand solid and indisputable evidence beyond the shadow of a doubt?
Are the writings of a handful of religious zealots who claimed to have had visionary experiences of their master and messiah being raised from the dead sufficient to convince a person living in the 21st century scientific era that we live in? David Koresh had a group of 70 something people who were willing to die for their belief that he was the son of god. Jim Jones had about 900 followers who were willing to kill themselves on his command. People can believe some crazy things. Shouldn't we reasonably demand solid evidence before committing our life to something? What is more probable: that a bunch of illiterate and uneducated religious people thought Jesus was their messiah and lord, and were so emotionally devastated after his death and crucifixion that some of them had dreams and/or visions of him and they convinced themselves that his death was actually part of god's plan and that he was raised to heaven, or that Jesus was actually the son of god?