Elijah, a forerunner to the messiah/god?

In answer to the video "The Quran and the Trinity"

Jn1:23/Mk1:3 is another case of the NT misrepresenting the HB and resorting to poor proof texting. Isa40 is addressing the exiled Jews, consoling them and telling them they will be returned to their land. It didnt happen anywhere near Jesus' time. It that context of promised return in the messianic era where Israel will take the center stage among the nations of the world, Isa40 speaks of straightening out a highway for God. The plain meaning is that the road will be cleared and eased for the fulfillement of God's will in returning the Jews. Nothing about a forerunner to the messiah (ie Elijah) nor the messiah himself.