No, down votes are extremely important here.
We can delete answers, but only for a few reasons:
- Doesn't answer the actual question that was asked
- Provides no evidence for its claims
Down votes are the main tool you have to say that an answer which addresses the question and provides some evidence or rationale for its conclusions is still problematic. If you think it is illogical, reads the scriptures poorly, or draws the wrong conclusions from the text, then down voting is what you should do.
Now I wouldn't say that there is no one here who ever down votes purely because of theological disagreement, just as there are partisan up votes too. But I'd encourage you to try to be a little more optimistic about our site community; don't assume that all or most down votes you've received are because of theological disagreement. Also practice voting well: if an answer makes its point well, even if you disagree with the conclusion, give it an up vote.
Also this request has come up thousands of times across the network, and SE staff have never given any indication that they'd consider it. Voting both up and down is seen as essential for quality control.