Well, there are many opinions. O believe in the divinity of Yeshua, but not in the triune nature of G-d (though I do not rule trinitarianism to be heretical, it is, in my belief, misguided). In my realm of belief, Yeshua is Hashem, in that Yeshua is merely the name attributed to G-d as he came within a human form in a human body. He was fully human, and fully a form of G-d. He is G-d, not a separate entity, so he did preexist. He came to teach on the Torah, to clarify it and to condemn certain aspects the oral tradition in Judaism, redacted in the Talmud (though not to reject it completely).
He, then, established himself as a tzadiki sacrifice, which can be used in the same form as the previous Temple sacrifices, to provide an automatic pass out of Geihinnom and into Paradise, much as the sin offerings did in the days of the Temple. No one is sinless except G-d alone, so only G-d could be the permanent sacrifice. The changes were, that non-Jews could now be provided with this automatic pass, and that this would provide a replacement for Jews in the soon-to-come time when sin sacrifice in the Temple would be impossible. However, Jews remain the people of G-d, and we are to continue upholding the Torah which G-d has given us, and to promote the Noachide Laws among the gentiles.
When covered by the permanent sacrifice, one will not enter into Geihinnom for punishment, and be allowed immediately into Paradise, just as anyone who was covered by a Temple sin sacrifice would have been in the days of the Temple. Someone who is not covered by the permanent sacrifice will enter into Geihinnom for a fair sentence based on a careful weighing out of their good deeds and their sins. After this, most souls will eventually be permitted into Paradise, only the most evil of souls and spirits (for example, the Adversary) being condemned to eternity in Geihinnom.
I believe, in the End of Days, G-d's human form, as Yeshua, will return to the Earth and rule over humanity in perfect righteousness. I believe firmly, as the Prophet wrote:
In the acharit-hayamim
the mountain of Hashem's house
will be established as the most important mountain.
It will be regarded more highly than the other hills,
and all the Goyim will stream there.
Many peoples will go and say,
"Come, let us go up to the mountain of Hashem,
to the house of the G-d of Ya'akov!
He will teach us about his ways,
and we will walk in his paths."
For out of Tziyon will go forth Torah,
the word of Hashem from Yerushalayim
He will judge between the nations
and arbitrate for many peoples.
Then they will hammer their swords into plowblades
and their spears into pruningknives;
nations will not raise swords at each other,
and they will no longer learn war.
Yesha'yahu 2:2-4