From my study and understanding, the main difference between Hebrew Israelites and Christianity is that Hebrew Israelites do not believe Jesus (Yeshua) is the Messiah/Savior. They believe him to be a prophet.
*and I think they use the spelling of "Yahshua")
Now, yes, there are different "sects" within this spiritual path and some of them do reference Jesus (Yeshua) as the "Messiah;" BUT they do not believe that Jesus came to render a "new" salvation but rather to "renew/restore" the old laws of Israel. ---These sects are called "MESSIANIC HEBREW ISRAELITES."
However, even these "groups" of Israelites are not in accordance with the basic tenets of Christianity: believing in the trinity (Father, Son, Holy Spirit) and salvation solely through accepting Jesus (Yeshua) as Savior/Redeemer.
The 5th chapter of Matthew tells us so.>>>>
[17] Think not that I am come to destroy the law, or the prophets: I am not come to destroy, but to fulfil.
[18] For verily I say unto you, Till heaven and earth pass, one jot or one tittle shall in no wise pass from the law, till all be fulfilled.