If you accept monotheism, then you believe that there is only one supreme being. You could worship the sun, a piece of carved rock, your toaster, a golden calf, your cult leader, or Gaia, the spirit of the earth.
Only worshiping one pagan symbol does not make you a default believer in God.
"I used to think god was the sun.
God is the sun, but God's so much more
Than the Earth and the stars
And all of creation.
God is Creator,
All in All."
(Ricki Byars Beckwith, RScP, and Rev. Dr. Michael Bexkwith, "Use Me.")