That is not true. Isaiah 12:2 Surely God is my salvation; I will trust and not be afraid. The LORD, the LORD, is my strength and my song; he has become my salvation."
And there are hundreds of other passages that say the same thing. The LORD (YHvH), G-d is our salvation. No mediator required or ever mentioned for all that matter.
“And there are hundreds of other passages that say the same thing. The LORD (YHvH), G-d is our salvation. No mediator required or ever mentioned for all that matter.”
What you say is partially true, and the New Testament attests that the faith of the Patriarchs was accounted to them as grace, whereby they received salvation. However, under the Covenant of Moses, faith was to be demonstrated by obedience to the Law. The Law, exemplified through the High Priest and the Temple rituals, served as a type of mediator between Israel and God. “For faith without works is dead”, one of our Apostles said, so if a Jew had faith, he would follow the Law, and if he did not follow the Law, he had not faith.
Now, in the Old Testament, God did promise a New Covenant to the people of Israel, which we believe has been established. If our belief is correct, the mediation of Christ begins with the inception of this New Covenant, which began at Christ’s death. It is no wonder, to a Christian then, that the Old Testament doesn’t speak of a personified mediator, since his role had not been revealed, and did not play the same role in that Covenant.