The pairing with Parashah Bereshit, which opens the Torah with the creation of the heavens and the earth, rests on the most direct link the whole annual cycle offers: this haftarah opens with Isaiah using the identical vocabulary of a creator who made the heavens and stretched them out and spread out the earth, language chosen specifically to echo Genesis's own opening rather than merely to resemble it by coincidence.
Beyond that shared creation language, the haftarah's description of light given to open blind eyes recalls the very first act of creation in Genesis, the separation of light from darkness, while the passage's closing insistence that God alone is the first and the last, with no god formed before or after Him, restates in prophetic terms the same absolute priority Genesis claims for its own account of the world's beginning.
The choice also serves the annual cycle's broader opening purpose: pairing the Torah's first reading with a passage that names creation, redemption and Israel's mission all at once gives the very first Shabbat of the yearly reading cycle a haftarah that gestures toward the whole story the year's reading will go on to tell, not only toward the single parashah it accompanies that week.