Even those who deny the form of God accept his form

In some  religions, because  the   greater emphasis on logic, the worshipper simply   forms  a conception of God  in the mind,  and  worships it.    They  do  not  accept   an  external form  of  God.       In  reality,   however,   all  these conceptions are forms of the Lord.

Chaitanya Shikshamrita, Bhaktivinoda Thakura