I'm personally quite proud of our question and answer quality. It's a big reason we still exist. One of the ways we do maintain that quality is by deleting posts that don't meet our standards.
However we still have an obligation to welcome new users and our standards take some getting used to. In particular, people who find our site via Google tend to assume we want answers stemming from some particular viewpoint (often a Christian one). If we delete such answers on sight, we risk losing out on potentially valuable contributors.
How do we balance the tension between our unusual standards and our need for new blood? Should we be using downvotes instead of deletion more often?
A case study to consider:
One of the answers to Why does the Scripture say that Abraham sacrificed his “only-begotten son”? was:
There is one more explanation: The sacrificial son was Ishmael.
Instead of working with the user to improve the answer quality by finding supporting documents and so on, I deleted the answer. I gave less than 6 hours for the community to fix the post. In retrospect, that was not a smooth move and I regret it. It would have been interesting to see how that answer played out and I screwed up the opportunity.