Jewish people believe in the Jewish faith just as Christians believe in the Christian faith. It like me asking why Christians dont believe in the big bang theory. Christians believe in what their faith tells them. Everybody has different beliefs
Jewish people believe there was a Jesus, they just don't believe he was the Son of God. They have for many hundreds of years believed god would send down someone different than Jesus as His son. That is what they have learned and what they believe. It's ok to believe that because in the United States of America we have a right to believe what we want. I am a Christian, but I have a lot of respect for Jewish people. I never say anything to them about what they believe is right or wrong. And they don't say anything to me about what I believe is right or wrong. By the way, Jewish people and Christian people believe in the same god, they just don't believe in the same SON OF GOD. hope this helps!!!
According to the prophets the Messiah, when he comes, will establish his kingdom on the earth and retake the throne of David. Since Jesus died without doing this they believe he cannot be the promised Messiah and so they wait for another.
Many Jews don't know much about the Messiah. The first century Jews were looking for a Messiah who was quite a different in their imaginations from the true Messiah. By the way, the name, Christ, means Messiah. Messiah means anointing or anointed one. The majority of the Jews were not looking for a sacrificial Lamb of God to take away their sins. They were looking for someone to destroy their physical enemies. This is a warning to anyone who tries to understand prophecy without divine revelation. There are many such reasoners among the Christians today, creating theologies about things that they don't understand. The real reason that most Jews don't accept Jesus Christ is because they are going about trying to establish their own righteousness, so they miss the free gift of God's righteousness. Many Christians, by the way, do the same thing and also only accept Jesus Christ in name. They don't receive the free gift of God's righteousness, which is available through the faith of Jesus. However, many do receive this gift today. http://www.seekfind.net/Why_dont_Jews_believe_in_Jesus.html
Historically the Jewish nation was often disobedient and even defiant toward God. They were separated from Him more than once then returned to Him. Finally God had enough and their hearts were hardened and their eyes blinded to the Truth. And it remains that way today. One day their eyes will be opened again.
They don't believe God is divisible. It's ludicrous to them to imagine a three-way Godhead. Father--yes. Son or Spirit--no! Most Jews I know fully believe that Jesus walked the earth. They just don't think He was God, the Messiah, or anything else related to their Heavenly Father.
I personally know many Jews who believe in Jesus. It's still rare but it does happen. But when Jews accept Jesus, they generally are considered to have left Judaism. However, their children are usually considered Jews, and messianic Judaism is in many ways similar to traditional services.
Because the Jews believe Jesus to be an IMPOSTURE & justifiably so. They refuse to give into the hoax of the "three headed monster"; meaning the trinity. They denounce the absurdity that their god is at per with a ghost - holy or unholy. They're right to believe that Jesus is the principal cause for their constant unjust sufferings for the last 2000 years. Let alone accepting Jesus as their savior, the Jews would be absolutely justified to prosecute Jesus for crimes against humanity - if they have a chance!
There is only One true Savior and that is God, not Jesus. In my experience, God is greater in saving us from the addictions of this world, and helps to heal the past wounds, through giving us additional hope and faith. If you love Jesus that is great, you can continue to love Jesus, but worship the Creator of Jesus.
To begin with, we need to remember that there were many Jews during Jesus' public ministry and afterward who DID accept Jesus as the Messiah. All of the twelve apostles were Jews, as were nearly all of Jesus' disciples and many early converts. Many of these early Jewish Christians were martyred for the faith - for example, St. Stephen, St. Barnabas, and St. Paul. Throughout the 2000-year history of Christianity, many Jews have come to accept Jesus and have converted to Christianity. A famous example from the 20th century is Edith Stein, who became Catholic and, later, a Carmelite nun. During World War II, she died in a Nazi concentration camp. She was recently canonized and is now revered as a saint of the Church. (My answer continues in the comments)