It’s one of the midrashim people know. Chazal say that Pinchas is Eliyahu. Both were kana’im, zealots in a positive way, who knew when and where to apply this characteristic.
In Sefer Melachim, Eliyahu asks Hashem to punish those steeped in idol worship to send a message once and for all regarding how terribly evil idolatry is. Hashem resists Eliyahu’s plea and says that at this time, He will only deal with a “kol d’mama dakah,” a soft voice. The reasons for this are not explained. However, Eliyahu continued being forceful with the people. It was then that Hashem told him he could no longer be His primary representative and asked him to go get Elisha and make him his student.
The stark comparison between the zealot personality of Eliyahu and of Pinchas, who is also called a kanai, creates a strong link to this section of Navi (Melachim 1, 18:46-19:21), and a perfect choice for the haftarah for Parshas Pinchas.
The Yalkut Shimoni on this parsha is one of the many midrashim that says Pinchas is Eliyahu. Obviously, if Pinchas was biologically the same person as Eliyahu that would mean that he lived from Yetzias Mitzrayim until the time of King Achav, approximately 600 years. This would be quite an anomaly given that the maximum age people lived at that time was the classic 120 years of Moshe Rabbeinu (a bracha we give each other to this very day). That doesn’t mean it couldn’t happen, only that it would be very unique. Then again, there are many things about Eliyahu that are exceptional, not the least of which is his ascending to Heaven while still alive.
There are clearly commentaries and even passages in Shas that do dispute the idea of Pinchas being biologically the same person as Eliyahu. They were similar in nature, no doubt, but were not actually the same people. So what does the midrash mean? Let us study a passage of Maharal (Ohr Chadash, page 101) who explains a major yesod, foundation, in understanding midrashim which say that two differently named people are actually the same person.
The Gemara in Megillah (12b) says that Memuchan, one of the seven advisors of Achashveirosh mentioned early in the Megillas Esther, was actually Haman. The Maharal refers us to Targum Sheni (2:1) where it says that when Achashveirosh regretted killing Vashti on the advice of his advisors, he had them all executed. If so, says the Maharal, Memuchan was not actually Haman, since Haman wasn’t killed at that time. What then do Chazal mean?
The Maharal explains that the intent is that both Memuchan and Haman were similar in nature; both were born under the mazal of ma’adim or Mars, known for “producing” those who are involved with blood (see Shabbos 156a), and had similar life goals. The upshot of the Maharal is that sometimes when Chazal say that two different people are really one, they do not mean it literally, but rather figuratively. In other words, sometimes they are the same person, and other times not. Thus, perhaps when Chazal say Pinchas is Eliyahu it is not meant in a literal sense. They were similar in many ways and had similar missions in life, but were not actually the same person.
Another Maharal relevant to our discussion explains a famous midrash regarding Og, King of Bashan, which seems to indicate that he lived a very long time. Rashi (Bereishis, 14:13) cites the midrash which says that Og was a survivor of the mabul, the flood at the time of Noach. How did Og survive? A different midrash says that he held on to the Ark. If taken literally, this means that although the Chumash is quite explicit regarding the entire world being destroyed except for the righteous Noach and his family, somehow Og was a survivor as well. The Maharal there questions a literal interpretation of this midrash. Og was known to be a wicked man, a rasha; why would Hashem allow him to live close to 1000 years and be killed by Moshe Rabbeinu?