Oneness of God

Hear, O Israel: The LORD our God is one LORD: Deut 6:4

For thou art great, and doest wondrous things: thou art God alone. Ps 86:10

Thus saith the LORD the King of Israel, and his redeemer the LORD of hosts; I am the first, and I am the last; and beside me there is no God. Isa 44:6

Now a mediator is not a mediator of one, but God is one. Gal 3:20

As concerning therefore the eating of those things that are offered in sacrifice unto idols, we know that an idol is nothing in the world, and that there is none other God but one. 1 Cor 8:4

The Hebrew word for One is 'Echad.

OT:259 'echad

(ekh-awd'); a numeral from OT:258; properly, united, i.e. one; or (as an ordinal) first:

KJV - a, alike, alone, altogether, and, any (-thing), apiece, a certain, [daily-], each (one), + eleven, every, few, first, + highway, a man, once, one, only, other, some, together,
(Biblesoft's New Exhaustive Strong's Numbers and Concordance with Expanded Greek-Hebrew Dictionary. Copyright (c) 1994, Biblesoft and International Bible Translators, Inc.)

The Greek word of One is Heis.
NT:1520 heis

(hice); (including the neuter [etc.] hen); a primary numeral; one:

KJV - a (-n, -ny, certain), + abundantly, man, one (another), only, other, some.
(Biblesoft's New Exhaustive Strong's Numbers and Concordance with Expanded Greek-Hebrew Dictionary. Copyright (c) 1994, Biblesoft and International Bible Translators, Inc.)