Where does the monotheism-polytheism clash peak in revelation?

Although most theists believe in One Supremely Powerful Creator of the universe, the greatest point of contention with regards to revelation is that:

• monotheists believe in God’s revelation as the only source of knowledge about faith and facts of the unseen, whereas,
  

• some polytheists believe in other sources of knowledge besides revelation, such as idols, stars, the deceased, jinn, etc; while others don't believe in revelation from God at all.

Thus, the position of proper monotheism with regards to revelation is that:

- God is the Source of knowledge. 

- God communicated with humans and conveyed knowledge, through revelation, to guide people. 

- Other gods, dead persons, stars, etc. are NOT sources of knowledge.  

Ibn Taimiyyah said: “Without God’s revelation, the mind would not be guided to necessary details of what brings benefit or harm in this worldly life or the Hereafter.” 

Thus, revelation has been sent down to clarify the details of facts beyond the mind or the physical world. It clarifies  details of belief and Characteristics of God,as well as the divine basis of morals and acts of worship.