Galatians 3:20

Now the mediator is not for one, but God is one.

1 Timothy 2:5

For [there is] one God and one mediator between God and human beings, the man Christ Jesus,

Deuteronomy 6:4

"Hear, Israel, Yahweh our God, Yahweh is unique.

Hebrews 8:6

But now he has attained a more excellent ministry, by as much as he is also mediator of a better covenant which has been enacted upon better promises.

Hebrews 9:15

And because of this, he is the mediator of a new covenant, in order that, [because] a death has taken place for the redemption of transgressions [committed] during the first covenant, those who are the called may receive the promise of the eternal inheritance.

Hebrews 12:24

and to Jesus, the mediator of a new covenant, and {to the sprinkled blood} that speaks better than Abel's [does].

Genesis 15:18

On that day Yahweh {made} a covenant with Abram saying, "To your offspring I will give this land, from the river of Egypt to the great river, the Euphrates river,

Genesis 17:1-2

When Abram [was] ninety-nine years old Yahweh appeared to Abram. And he said to him, "I [am] El-Shaddai; walk before me and be blameless

Job 9:33

There is no arbiter between us [that] he might lay his hand on both of us.

Acts 12:20

Now he was very angry with the Tyrians and Sidonians. So they came to him with one purpose, and [after] persuading Blastus, {the king's chamberlain}, they asked for peace, because their country was supported with food from the king's country.

Romans 3:29-30

Or [is God] the God of the Jews only? [Is he] not also [the God] of the Gentiles? Yes, also of the Gentiles,

Galatians 3:17

Now I am saying this: the law, that came after four hundred and thirty years, does not revoke a covenant previously ratified by God, in order to nullify the promise.

Treasury of Scripture Knowledge

Summary

Now a mediator is not a mediator of one, but God is one.

Bible References

A mediator is

Job 9:33
There is no arbiter between us [that] he might lay his hand on both of us.
Acts 12:20
Now he was very angry with the Tyrians and Sidonians. So they came to him with one purpose, and [after] persuading Blastus, {the king's chamberlain}, they asked for peace, because their country was supported with food from the king's country.
1 Timothy 2:5
For [there is] one God and one mediator between God and human beings, the man Christ Jesus,

But

Galatians 3:17
Now I am saying this: the law, that came after four hundred and thirty years, does not revoke a covenant previously ratified by God, in order to nullify the promise.
Genesis 15:18
On that day Yahweh {made} a covenant with Abram saying, "To your offspring I will give this land, from the river of Egypt to the great river, the Euphrates river,
Genesis 17:1
When Abram [was] ninety-nine years old Yahweh appeared to Abram. And he said to him, "I [am] El-Shaddai; walk before me and be blameless
Deuteronomy 6:4
"Hear, Israel, Yahweh our God, Yahweh is unique.
Romans 3:29
Or [is God] the God of the Jews only? [Is he] not also [the God] of the Gentiles? Yes, also of the Gentiles,

General references

Deuteronomy 5:3
[It was] not with our ancestors [that] Yahweh made this covenant, [but with] these [of] us [who are] here alive today.
Romans 3:30
since God [is] one, who will justify {those who are circumcised} by faith and {those who are uncircumcised} through faith.
James 2:19
You believe that God is one; you do well. Even the demons believe, and shudder!