Some of what jesus said in the sermon was already said. There’s a saying that there’s nothing new under the sun. Many of the things attributed to jesus had already been attributed to guys like Buddha and Krishna. Some of his sayings were already in prayer chants.
Osisris had already been a savior god that had died for three days and when during his annual celebration the people ate bread and drank beer as a representation of his body. When the Greeks took over and combined his likeness with that of several Greek gods like Dyonisis it switched to bread and wine.
Man has attributed many great saying and deeds to their god which ever god they worshipped at the time. Again “nothing new under the sun” , but let’s not forget Jesus wasn’t all that great for he told his followers in the stories of the Bible that non believers should be killed.