A great deal of early Christianity is anti-thematic to Judaism at that time.
In Judaism G'd is considered non-corporeal. So a son coming down, being human, dying (human trait), and rising, are all outside of Judaism at the time. Evidence of this belief in Judaism includes that Jews were called "atheists" by other groups of people at that time for their insistence that G'd doesn't have a body nor any worldly presentation.
In Judaism the existence of three G'd presentations, one being human, is borderline worship of idols (a human as a G'd). It's why belief in Jesus by a Jewish person, makes them an ex-patriot to Judaism. It put them outside Judaism and they'd have be make teshuva (repentance) to return.
In Judaism, sins are only the responsibility of the sinner, and can only be forgiven by the actions of the sinner to repent and change. There is no original sin taught in Judaism in any of the sacred or study texts (such as Talmud) which reflect beliefs from the turn of the millennium. Since you aren't born with original sin, there is no need for saving from it.
In Judaism, the messiah will bring peace on earth and an end to all suffering. There is no 2nd coming concept. It's also not a particularly important concept in the 2 millennia since. At the time, during the fight with the Roman's it was a hopeful idea being talked about. The messiah is supposed to come from the house of David, be a descendant of King David. Jesus is not. Others at the time were considered for the title, such as Bar Kokhba who lead one of the most successful rebellions against the Romans, and was thought to be by Rabbi Akkiva. When it was unsuccessful, it was considered a mistaken idea. It's thought that Bar Kokhba met more of the criteria than Jesus.
https://www.jewishvirtuallibrary.org/rabbi-akiva
A site with a lot of the basic concepts in Judaism is http://www.jewfaq.org. Reading through, one can see how concepts differ from Christianity.
There are also similarity in how G'd is taught. The idea of one g'd for all the world, being all powerful, was different than the beliefs of others around the Jews, and Christianity continued that belief.
Early Christianity borrows a lot from the pagans around it. However, it used that virtually rather than literally. For example, some local communities sacrificed live people to save their communities from sin. There is much debate how much of that borrowing is by the original apostles, and how much is from later interpretations.
Judaism had considerable elements that were intentionally the opposite of the communities around them. For instance, the belief that someone else can't die to save you from anything. With that, the idea in kosher laws around blood, are opposite to the drinking of blood to gain power that was used around them.
There are books written on the topic. I don't remember the names of ones I read parts of, but there are good sources on these concepts from early Christianity.
