Bible Verses About Unity of God: A ground for obeying him exclusively

Know therefore this day, and lay it to thy heart, that Jehovah he is God in heaven above and upon the earth beneath; there is none else.

And thou shalt keep his statutes, and his commandments, which I command thee this day, that it may go well with thee, and with thy children after thee, and that thou mayest prolong thy days in the land, which Jehovah thy God giveth thee, for ever.