That there is One God is taught throughout God's Word:
"Now see that I, even I, am He, and there is no God besides Me." Deuteronomy 32:39.
"I am the first and I am the last and there is no God besides Me. " Isaiah 44:6
"I, even I, am the Lord, and besides Me there is no Savior." Isaiah 43:10-11
That Jesus is that one God is also taught:
"I am the First and the Last. I am He who lives, and was dead, and behold, I am alive forevermore." Revelation 1:17
"I am the Alpha and the Omega, the first and the last, the beginning and the end. I, Jesus, have sent my angel to testify to you these things for the churches. I am the root and the offspring of David, the bright and morning star." Revelation 22;13,16
"Philip said to Him, “Lord, show us the Father....Jesus said to him, “Have I been with you so long, and yet you have not known Me, Philip? He who has seen Me has seen the Father; so how can you say, ‘Show us the Father’? John 14:8,9
"I and My Father are one.” John 10:30