I cannot give a blanket answer, but, in general, not only was the Messiah the overarching reason to even call out a chosen people, bring them into the knowledge of God, make them into a people who bring God's words to the world. And be the bloodline through which God/Messiah enters the world.
There is so much in the OT that foreshadows Christ: Abraham willing to sacrifice his son; The bronze serpent Moses lifted up, that all who look upon shall live; the rock that Moses struck that produced life-giving water.
Even the tabernacle that the priest entered was covered in dull badger skins on the outside, yet the inner curtain was beautifully woven material. Christ was man on the outside, plain, just like us, but on the inside He was the everlasting God, Holy and perfect.
A book called, Miracle of the Scarlet Thread opened my eyes to all the Messianic symbolism and foreshadowing in the OT.