What do you mean, exactly, by, "Speaks for God"? For example, people of the Mormon Church claim they speak for God in announcing the Catholic Church is in apostasy. Those who say they "speak for God" when they say vote for a particular candidate. Neither "speaks for God".
On the other hand, there are those who proclaim God's word--i.e., that sins are forgiven or that Jews were Chosen--i.e., set apart for a specific purpose. The Ten Commandments may be another example.
And here we get to the crux of the matter--and this reaches beyond religion/faith. Instead of opposition to "God", we can substitute any number of words here. Opposition to the government, to the Democratic Party, to the Republican Party, to Science to name just a few.
Any/all of those positions should be based on fact and logic, not on feelings, or the say-so of anyone, no matter how highly placed. First, go to the source. Who actually said it and what was the motivation behind it. If one supports the statement, what is the logic, facts for supporting it? Did God actually say to vote for a certain person? If he did not, then who said God said this, and what was the motivation for that statement?
I can point to any number of reasons I may not be in favor of Kamala Harris for President, much of it based on what is seen in the media and the positions she takes on various issues. However, I would not say anything against her personally for the sole reason I know for a fact when she was Senator she was kind and professional towards my daughter. She is not just a name to me, and nor should any candidate be to any of us.