In the Old Testament, a requirement of a priest was to be born into the family of priests. Those, such as Moses and Aaron, were born into the tribe of Levi.
No longer do we have to go to a priest to offer sacrifices. Today Jesus is our high priest who mediates not only for the Jews but for all people, according to Hebrews 7:11-22.
Unlike the priests in the Old Testament who were born into the family of priests, Jesus did not become a priest by being born into it. Jesus our high priest was born into the tribe of Judah which means "praise." Jesus became a high priest forever by the order of Melchizedek who has no beginning and no end.
The laws of the Old Testament never made anything perfect. Today we have a better covenant. Jesus is the one who guarantees a better covenant of God for us. The first covenant did not include everyone, only the Jews. However, this better covenant includes everyone.
Jesus came to the earth as a legitimate priest who was washed in water at His baptism and anointed by God as evident by the dove who landed on Him and God said, "This is my son in whom I am well pleased."
Jesus is our high priest, and our new covenant is a better covenant because the old one is obsolete, out of date and will soon disappear (Hebrews 8:13).