John 17:3 (KJV)

And this is life eternal, that they might know thee the only true God, and Jesus Christ, whom thou hast sent.

1 Corinthians 8:5-6 (KJV)

For though there be that are called gods, whether in heaven or in earth, (as there be gods many, and lords many,) But to us there is but one God, the Father, of whom are all things, and we in him; and one Lord Jesus Christ, by whom are all things, and we by him.