If the pastor or elder you ask doesn't know him well, he can guide you to a trustworthy source that knows him better.
If you know the man well or at least better than what I've just described, but you are not sure whether you are interested in him, I'd encourage you to at least take some time to get to know him before giving an unequivocal "no." Keep in mind that this is different from feigning interest when there isn't any.
The idea is to remove that period of confusion or vulnerability for the woman by being forthright about what level of intention or commitment exists (a la 1 Thessalonians 4).
You probably won't know at this stage how things are going to ultimately turn out regarding marriage (that's why you date), so you need not communicate that right away.
So with all that said, let's consider how the principle of caring for one another well in the early stages of a relationship might look.