That veers into Great Debates territory. There’s a difference, for example, between respecting that smoking is a risky habit and accepting that you’re actually killing yourself. There’s a strong argument to be made that the Christianity which Jesus taught was little more than a variant of Jewish Neoplatonism, but that is not the Christianity recorded in the orthodox works passed down to us today and the texts that we have, which are accepted to be from the 1st century, do not support that argument.
Plato does explicitly mention Zoroaster in Alcibiades I, so clearly he was aware of the religion. How much that influenced his ideas, positively or negatively, I would leave up to philosophy majors.