To answer the question we must first look at what was wirtten:
11 'Phinehas, the son of Eleazar, the son of Aaron the priest, hath turned My wrath away from the children of Israel, in that he was very jealous for My sake among them, so that I consumed not the children of Israel in My jealousy.
12 Wherefore say: Behold, I give unto him My covenant of peace;
13 and it shall be unto him, and to his seed after him, the covenant of an everlasting priesthood; because he was jealous for his God, and made atonement for the children of Israel.'
So it is clear from the Torah that there are two never ending families that will intercede with God on behalf of mankind. Essentially that is what is meant by Messiah. One who intercedes on behalf of mankind and therefore saves the people. As Karaite that being the families of Aaron and David. If I was Samaritan, then it would be the families of Aaron and Joseph. Ultimately, regardless of these differences, it is always about two Messiahs.