Is the world at peace right now? Has it ever been since the coming of Jesus? There are many reasons Jews do not accept Jesus as the messiah. I'm not going to go into all of them now but I will make a couple points. I think the biggest one is that the messiach will mark the coming of Ein Sof, the healing of the world, where nation shall not fight against nation, swords shall be beaten into plowshares, etc.
Another sticking point is the whole idea of the divinity of jesus and the necessity to believe in him as such to be 'saved' from some kind of hell. Personally, that whole concept does not make much sense to me. Judaism does not compel any particular belief in the hopes of future reward. I try to do good for the sake of bringing myself closer to HaShem in this life, to do my part in making this world a better place.
I do not deny that Jesus was not a good person, and I could possibly be convinced of his prophethood, but I can't be convinced in his divinity or his claims to being messiach.
There is one good reason why some Jews do not accept Jesus as the Messiah. and why some Jews do accept Jesus as the Messiah.
If you study the old testament and the new testament, you will find the good fig and the bad fig. Which at the time while Jesus was here on earth, Jesus curse the bad fig.
The question is, Who is the good fig? and who is the bad fig?
Unto which you also have the good Christians and the bad Christians.
The question is, How do you tell them apart?
With the same question, How would you tell the good fig, From the bad fig?
The Answer to all of this, Lays within the Pages of the Scriptures ( Bible )