Could someone other than a Levite legitimately serve as a priest?

Question

There was in the days of Herod, the king of Judea, a certain priest named Zacharias, of the division of Abijah. His wife was of the daughters of Aaron, and her name was Elizabeth. (Luke 1:5)

Zacharias was both a Levite and a priest.

Now this is the testimony of John, when the Jews sent priests and Levites from Jerusalem to ask him, “Who are you?” (John 1:19)

This says that two different types, priests and Levites were sent from Jerusalem to John.

I can understand how a Levite which describes ancestry, would not be a priest, which describes a duty or type of service. In fact that would be an accurate description for John the Baptist. He was a Levite yet he was not serving as a priest.

Was it possible for someone who was not a Levite to legitimately serve as and be called a priest?

Answer 1

This says that two different types, priests and Levites were sent from Jerusalem to John.

All priests were Levites. All Levites were not priests.

Levi was the father of Gershon, Kohath, and Merari. Of these three, Kohath was the father of Amram; Amram was the father of Aaron. Specifically, the sons of Aaron were the priests.

In Exo. 28:1, it is written,

¹ Now take Aaron your brother, and his sons with him, from among the children of Israel, that he may minister to Me as priest, Aaron and Aaron’s sons: Nadab, Abihu, Eleazar, and Ithamar. ^{NKJV, 1982}

The Levites (sons of Levi) who were not priests (sons of Aaron) did work in the Temple, but they did not perform tasks specifically assigned to the priests.