THE BIBLE says

"Hear, O Israel: the LORD our God, the LORD is one!" (Deut.6:4)

JESUS says

"Before Abraham was born, I am!" (John 8:58)

"I and the Father are one." (John 10:30)

"When the Counsellor comes, whom I will send to you from the Father, the Spirit of truth who goes out from the Father, He will testify about Me." (John 15:26)