just wondering, some questions.

im not sure if this is where this thread belong, but anyways i was just wondering why people think the antichrist is gonna be jewish because wasnt jesus a jew? and why is it anti christish to rebuild solomans temple? and isnt the foundation of christianity built on the fact that jesus died for you so alls you have to do is repent,
so alls the jews do is follow the rules that the lords and god set down for them just in case jesus didnt die for them. and the christians are basically founded on the beliefs that alls they have to do is repent. i mean i can uderstand if its a true repent, but as far as im aware most christians dont truthfully repent they just say they are sorry without being truthfully sorry. i understand the fact that the jews wanna live perfect. its not that hard to understand. so could the potential answer be trying to live perfect and if you do sin that repentence can save you if your truthfully sorry for what you've done. ohh and sorry if this is in the wrong board topic.