The Levites were the tribe that were of the priestly class.Their was one High priest and he served untilled he died.The levites were responsible for all the duties in the temple and for all the scarificing of the animals for the cleansing of the people sin.

I the Old Testament, before Jesus time, the priestly class was through Levi, Isaacs son, and the Messianic tribe was through Judah...where Christ descended . So, that being fulfilled, I would think the "classes" ended...there is not "priestly class"..HE opened to ALL, so,I would reason whomever wants to dedicate his life to God as preacher or priest , minister,etc., can... the 12 Apostles Jesus chose were ordinary men, I don't think HE chose a certain "class" of men... hope may help.....

"In our Lord's time, who was the priestly class found among?" First, when asking questions about Judaism, using the epithet "our Lord" is not only off-putting, it is offensive. Jesus is not "our Lord" in Judaism. To answer the question I assume you were trying to ask (to wit: "In Jesus' time, who were the priests?"), the answer is the descendants of the sons of Aaron, Moses's brother. When it talks about "the priests and the Levites did [whatever]" (when it refers to them all as a group), it's actually gibberish, possibly indicative of an ignorance on the part of the writer that the priests (descendants of Aaron) _are_ Levites ("Levites" are descendants of Levi [one of Jacob/Israel's sons] an ancestor of Aaron's and Moses'). To this day, the priests (kohanim) are still around, and they're still priests [although without the Temple they can't perform their duties as priests], some of them are even rabbis. (Some common surnames of priests are Cohen, Kohn, Kagan, Kahn, Katz, etc.) The Levites are around as a larger group still as well. (Some common Levites' surnames are Levy, Levi, Levine, etc.) There was no "priestly class" [neither then, nor now], there were, and are, "priestly families" from the "priestly clan", if you will.