Why Jews and Muslim does not accept that Jesus was fully man and fully God?

While Christians do ??? The story of Bible N.T sounds like enough evidence and proof that Jesus is a God? I mean especially since he resurrected from the death and stayed on the earth for 40 days, then rose ??? IF this event actually took place and it seems like it did because of actual eye witness by both his followers and non-followers at the time... what else do we need ????? yet still Jews and Muslim deny him. I do not get it.... but I want to learn WHY ~!?? May be I may want to be a Jewish, or Muslim.... I am just learning from Japan we do not have much religious back ground here... its all foreign to me.