Many of the Gospels were edited hundreds of years after Jesus lived, with the idea of discrediting the Jews, who were rivals with the Christians.
One of the first things they did was to change the Sabbath to Sunday, as a sop to the Roman Priests whose traditional worship day was Sunday .
Well I don't know about the Gospels being edited hundreds of years later, but I do know the Jews and Christians were rivals for converts. I think that actually this rivalry was not really understood until recently and I also think that when New Testament scholars started actually working with Jewish scholars and getting their help on exegesis there has been a more favorable understanding about the Jews of the New Testament.
Simply not so. Nothing in any of the Gospels in any way discredits Jews as such. It's the Pharacees that the Lord denounced for their hypocrisy, not the people in general.