Galatians 3:20

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

1 Timothy 2:5

For there is one God, and one mediator between God and men, the man Christ Jesus;

Deuteronomy 6:4

Hear, O Israel: The LORD our God is one LORD:

Hebrews 8:6

But now has he obtained a more excellent ministry, by how much also he is the mediator of a better covenant, which was established upon better promises.

Hebrews 9:15

And for this cause he is the mediator of the new covenant, that by means of death, for the redemption of the transgressions that were under the first covenant, they who are called might receive the promise of eternal inheritance.

Hebrews 12:24

And to Jesus the mediator of the new covenant, and to the blood of sprinkling, that speaks better things than that of Abel.

Genesis 15:18

In the same day the LORD made a covenant with Abram, saying, Unto your descendants have I given this land, from the river of Egypt unto the great river, the river Euphrates:

Genesis 17:1-2

And when Abram was ninety years old and nine, the LORD appeared to Abram, and said unto him, I am the Almighty God; walk before me, and be you perfect.

Job 9:33

Neither is there any mediator between us, that might lay his hand upon us both.

Acts 12:20

And Herod was highly displeased with them of Tyre and Sidon: but they came with one accord to him, and, having made Blastus the king's chamberlain their friend, desired peace; because their country was fed by the king's country.

Romans 3:29-30

Is he the God of the Jews only? is he not also of the Gentiles? Yes, of the Gentiles also:

Galatians 3:17

And this I say, that the covenant, that was confirmed before by God in Christ, the law, which was four hundred and thirty years after, cannot disannul, that it should make the promise of no effect.

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
Neither is there any mediator between us, that might lay his hand upon us both.
Acts 12:20
And Herod was highly displeased with them of Tyre and Sidon: but they came with one accord to him, and, having made Blastus the king's chamberlain their friend, desired peace; because their country was fed by the king's country.
1 Timothy 2:5
For there is one God, and one mediator between God and men, the man Christ Jesus;

But

Galatians 3:17
And this I say, that the covenant, that was confirmed before by God in Christ, the law, which was four hundred and thirty years after, cannot disannul, that it should make the promise of no effect.
Genesis 15:18
In the same day the LORD made a covenant with Abram, saying, Unto your descendants have I given this land, from the river of Egypt unto the great river, the river Euphrates:
Genesis 17:1
And when Abram was ninety years old and nine, the LORD appeared to Abram, and said unto him, I am the Almighty God; walk before me, and be you perfect.
Deuteronomy 6:4
Hear, O Israel: The LORD our God is one LORD:
Romans 3:29
Is he the God of the Jews only? is he not also of the Gentiles? Yes, of the Gentiles also:

General references

Deuteronomy 5:3
The LORD made not this covenant with our fathers, but with us, even us, who are all of us here alive this day.
Romans 3:30
Seeing it is one God, who shall justify the circumcision by faith, and uncircumcision through faith.
James 2:19
You believe that there is one God; you do well: the demons also believe, and tremble.