"they" meaning the people that organized the new testament and the false belief system centered around their idea of the jewish messiah.Who is 'they'? It was JESUS who corrected the false ideas or those who had empty religion, in other words people who went through the motions but missed what is most important. It's up to each individual to decide if they believe what Jesus said is true or not. Although most Jews rejected Jesus, (which itself was prophesied in their own scriptures, btw) some of the early Christians were Jews who followed Jesus.
As for the other things you said, read the excellent book 'The Case for Christ' by Lee Strobel. It thoroughly goes through all the common objections and corrects the misconceptions people have about the bible.