Deuteronomy 6:4 (American Standard Version)
4 Hear, O Israel: Jehovah our God is one Jehovah:
Deuteronomy 6:4 (Young's Literal Translation)
4`Hear, O Israel, Jehovah our God [is] one Jehovah;
The above texts, show that God Almighty, whose personal name is Jehovah [as traditionally rendered in English], is ONE.
At John 10:30, Jesus the Christ says:
John 10:30 (King James Version)
30I and my Father are one.
How is this to be understood?
In light of all else that is recorded in the Bible, including in the Book of John, such as: John 5:19, 30; John 8:42; John 6:38; John 12:49; John 14:28; John 20:17, 31, we know, that Jesus was NOT saying that He was his Father, Jehovah.
Let us look at John 17 for clarification.
John 17:20-22 (American Standard Version)
20 Neither for these only do I pray, but for them also that believe on me through their word;
21 that they may all be one; even as thou, Father, art in me, and I in thee, that they also may be in us: that the world may believe that thou didst send me.
22 And the glory which thou hast given me I have given unto them; that they may be one, even as we are one;
Evidently, Jesus meant ONE in PURPOSE, ONE in UNITY.