But then, you do deny New Testament (Bible) revelation in its entirety. The New Testament attests to the Deity of Jesus Christ and His Sonship to the Father. So does the Old Testament, by the way, seen clearly once NT revelation is accepted.
Who was Jesus Christ, in your estimation.
He claimed to be God manifest in the flesh, and His apostles taught it. Either He is Who He said He is, or He was the worlds greatest master deceiver. Which(?), in your view.
Neither. There are a lot of other options in there.
As historical speculation, I suspect there was such a preacher named Joshua at that time, simply considering the commonality of that name. Monty Python's Life of Brian exaggerated, but the scene with the street of rival preachers was not all that far off the historical truth.
That said, this Joshua attracted a following and had some wisdom in what he said. Quite possibly, he got in trouble with the Roman law. After his death, his followers collected stories on him, some accurate; some the works of other men, attributed to Jesus, some -- well, George Washington had his Parson Weems.
In a religious sense, it is irrelevant to me. Judaism in unusual in that it sees itself as the religion of one people only -- the Tribe of Israel -- but does not deny that people of other religions may be righteous. Furthermore, Jewish belief is that the righteous non-Jew has the same reward in the afterlife as the righteous Jew. The difference is that the non-Jew is subject to Noahic law; the Jew is subject to Jewish.
Christianity is the way God for the righteous Christian. Islam is the way to God for the righteous Muslim (not as many of them around, anymore, a there used to be). Buddhism is the way to God for the righteous Buddhist. Atheism is the way to God for the righteous atheist -- and won't they be pleasantly surprised?