When I used to "practice magic" it was understood that just because you affirm, envision, call forth or otherwise attempt to manifest your desires doesn't mean that it will happen. It's understood that (except for "high magic") it's not our will being done, but God/dess's. Phyllis Curott focuses on this point A LOT. Like I said, she is more spiritual in her approach and not so "gimme gimme" oriented (as some pop wiccan authors are).
For me - magic, ritual, incantations, meditation, prayer - are ways to help ME connect to the Divine.
There are other magical traditions that believe you can force God/dess or nature or whatever to bend to your will. High Magic traditions are more of this mindset (like Golden Dawn) and other hermetic lineages. I don't care for them much.